The principle of equivalence and projective structure in space-times

This paper discusses the extent to which one can determine the space-time metric from a knowledge of a certain subset of the (unparametrised) geodesics of its Levi-Civita connection, that is, from the experimental evidence of the equivalence principle. It is shown that, if the space-time concerned is known to be vacuum, then the Levi-Civita connection is uniquely determined and its associated metric is uniquely determined up to a choice of units of measurement, by the specification of these geodesics. It is further demonstrated that if two space-times share the same unparametrised geodesics and only one is assumed vacuum then their Levi-Civita connections are again equal (and so the other metric is also a vacuum metric) and the first result above is recovered.Comment: 23 pages, submitted to Classical and Quantum Gravit

On the Theory of Killing Orbits in Space-Time

This paper gives a theoretical discussion of the orbits and isotropies which arise in a space-time which admits a Lie algebra of Killing vector fields. The submanifold structure of the orbits is explored together with their induced Killing vector structure. A general decomposition of a space-time in terms of the nature and dimension of its orbits is given and the concept of stability and instability for orbits introduced. A general relation is shown linking the dimensions of the Killing algebra, the orbits and the isotropies. The well-behaved nature of "stable" orbits and the possible miss-behaviour of the "unstable" ones is pointed out and, in particular, the fact that independent Killing vector fields in space-time may not induce independent such vector fields on unstable orbits. Several examples are presented to exhibit these features. Finally, an appendix is given which revisits and attempts to clarify the well-known theorem of Fubini on the dimension of Killing orbits.Comment: Latex, 19 pages, no figur

Spatial learning and memory in the tortoise (Geochelone carbonaria)

A single tortoise (Geochelone carbonaria) was trained in an eight-arm radial maze, with the apparatus and general procedures modeled on those used to demonstrate spatial learning in rats. The tortoise learned to perform reliably above chance, preferentially choosing baited arms, rather than returning to arms previously visited on a trial. Test sessions that examined control by olfactory cues revealed that they did not affect performance. No systematic, stereotyped response patterns were evident. In spite of differences in brain structure, the tortoise showed spatial learning abilities comparable to those observed in mammals

The concept of sexual exploitation in legislation relating to persons with intellectual disability

The focus of this paper is on the use of the concept of sexual exploitation in legislation concerning sexual expression by persons with mental impairment, with particular emphasis on persons with intellectual disability. Two main statutory approaches have been adopted in Australian jurisdictions. The first is prohibition of sexual acts between a person with intellectual disability and others who, by virtue of their employment, are in a position of ascendancy over that person. The second is the prohibition of sexually exploitative acts by any person towards a person with an intellectual disability. The major aim in this article is to critically examine these approaches and evaluate them according to the standards of being non-discriminatory, minimally restrictive of rights, and enforceable. It is argued that comprehensively cataloguing sexually exploitative acts is untenable, with the result that prohibition of all sexual exploitation is unenforceable. The alternative, namely legislation that prohibits sexual relations with any person employed to render any kind of service to the intellectually disabled person, would further restrict an already limited number of potential sexual partners. We suggest that a more useful approach would be to prohibit sexual activity in one-on-one relationships whose scope is commonly understood to exclude such acts, while allowing relations between workers or caregivers and the persons to whom they do not directly render services. This mechanism would have to be narrowly defined to have the desired effect of affording protection to vulnerable persons while preserving their right to sexual expression

Using the interpersonal reactivity index to assess empathy in violent offenders

The Interpersonal Reactivity Index (IRI), developed by Davis (1980), provides an excellent multidimensional measure of empathy for the general adult population, the domain for which it was developed. Its use has subsequently expanded into other areas, for example criminal psychology. In this domain empathy is a critical variable in theoretical accounts of criminality and particularly of violence. For many researchers within the field of criminal psychology, the IRI has become the instrument of choice for the assessment of empathy. However, the psychometric properties of the scale, when used with a criminal population, have not been investigated. This paper reports the results of an investigation into the reliability and component structure of the IRI using a sample of violent offenders. The Personal Distress subscale was found not to be reliable when used in an offender population. Furthermore, when used to assess offenders, principle components analysis did not confirm the four-subscale structure of the IRI. Possible explanations for these findings are discussed in relation to offender assessment in general

Self-similar static solutions admitting a two-space of constant curvature

A recent result by Haggag and Hajj-Boutros is reviewed within the framework of self-similar space-times, extending, in some sense, their results and presenting a family of metrics consisting of all the static spherically symmetric perfect fluid solutions admitting a homothety.Comment: 6 page

A Study for a Tracking Trigger at First Level for CMS at SLHC

It is expected that the LHC accelerator and experiments will undergo a luminosity upgrade which will commence after several years of running. This part of the LHC operations is referred to as Super-LHC (SLHC) and is expected to provide beams of an order of magnitude larger luminosity (1035cm-2sec-1) than the current design. Preliminary results are presented from a feasibility study for a First Level Tracking Trigger for CMS at the SLHC using the data of the inner tracking detector. As a model for these studies the current CMS pixel detector with the same pixel size and radial distances from the beam has been used. Monte Carlo studies have been performed using the full CMS simulation package (OSCAR) and the occupancy of such a detector at SLHC beam conditions has been calculated. The design of an electron trigger which uses both the calorimeter energy depositions and the pixel data to identify isolated electrons and photons has been investigated. Results on the tracker occupancy and the electron trigger performance are presentedComment: Presented at LECC, Heidelberg 200

Recent Studies of Nonequilibrium Flows at the Cornell Aeronautical Laboratory

Vibrational relaxation in supersonic nozzle diatomic gas flow, nonequilibrium effects in high enthalpy airflow over thick wedge flat plates, and reentry nonequilibrium flow field