Focus of attention in an activity-based scheduler

Earlier research in job shop scheduling has demonstrated the advantages of opportunistically combining order-based and resource-based scheduling techniques. An even more flexible approach is investigated where each activity is considered a decision point by itself. Heuristics to opportunistically select the next decision point on which to focus attention (i.e., variable ordering heuristics) and the next decision to be tried at this point (i.e., value ordering heuristics) are described that probabilistically account for both activity precedence and resource requirement interactions. Preliminary experimental results indicate that the variable ordering heuristic greatly increases search efficiency. While least constraining value ordering heuristics have been advocated in the literature, the experimental results suggest that other value ordering heuristics combined with our variable-ordering heuristic can produce much better schedules without significantly increasing search

Heteroduplex analysis of tra delta f' plasmids and the mechanism of their formation

Four tra delta FargG+ plasmids, derived from matings between Hfr AB312 and a recA recipient, have been shown to have deletions of at least 50% of the F genome, including the region in which the tra genes map. The mutant plasmids do contain the F genes required for plasmid maintenance. Correlations can be made between, on the one hand, the F genes present on the tradelta F' plasmids and the F genes transferred early by an Hfr donor, and, on the other hand, the F genes deleted from the tradelta F' plasmids and the F genes transferred late by an Hfr donor. A biased representation of proximally and distally transferred chromosomal markers among the tradelta F' elements was also demonstrated. Taken Taken together, the asymmetrical representation of Hfr genes and the cis dominance of the Tra phenotype of these mutants can best be explained by the hypothesis that the tradelta F' plasmids are formed by repliconation of the transferred exogenote in a recA recipient

Sport and Incarceration: Theoretical Considerations for Sport for Development Research

Despite a rapid expansion in research on Sport for Development (SfD), there remain numerous untapped veins of exploration. This article makes a novel argument for increasing the theoretical and substantive depth of SfD research by linking it to the relatively small, yet developing, body of literature on sport and incarceration. Drawing from the emergent field of carceral geography and the literature on prison sport, this article provides critical theoretical considerations for SfD programs that occur in ‘compact’ sites of confinement, such as prisons or refugee camps, or are enmeshed in ‘diffuse’ manifestations of carcerality. Given the structures of inequality that have led to the confinement of more than 13 million people in prisons, refugee camps, and migrant detention centres across the globe, as well as the multitude of ways that groups and individuals are criminalized and stigmatized in community settings, there are compelling reasons for SfD research to more deeply engage with concerns of space and carcerality as they relate to sport. As such, this article provides an important foundation for future analyses of SfD and carcerality, and signposts some potential ways forward for a deepening of theoretical perspectives in SfD research

Dynamic mimicry in an Indo-Malayan octopus

During research dives in Indonesia (Sulawesi and Bali), we filmed a distinctive long-armed octopus, which is new to science. Diving over 24 h periods revealed that the 'mimic octopus' emerges during daylight hours to forage on sand substrates in full view of pelagic fish predators. We observed nine individuals of this species displaying a repertoire of postures and body patterns, several of which are clearly impersonations of venomous animals co-occurring in this habitat. This 'dynamic mimicry' avoids the genetic constraints that may limit the diversity of genetically polymorphic mimics but has the same effect of decreasing the frequency with which predators encounter particular mimics. Additionally, our observations suggest that the octopus makes decisions about the most appropriate form of mimicry to use, allowing it to enhance further the benefits of mimicking toxic models by employing mimicry according to the nature of perceived threats

An investigation into motor pools and their applicability to a biologically inspired model of ballistic voluntary motor action

This study investigates the properties of motor pools in the human motor control system. The simulations carried out as part of this study used two biologically inspired neuronal models to simulate networks with properties similar to those observed in the human motor system (Burke, 1991). The Synchronous neuronal model developed as part of this study explicitly models the input/output spike train and frequency relationship of each neuron. The motor pool simulations were carried out using the INSIGHT TOO simulation software developed as part of this study. INSIGHT TOO is a flexible neural design tool that allows the visual interactive design of network connectivity and has the power of a node specification language similar to that of BASIC that allows multi-layer, multi-model networks to be simulated. The simulations have shown that the motor pools are capable of reproducing commonly observed physiological properties during normal voluntary reaching movements. As a result of these findings a theoretical model of ballistic voluntary motor action was proposed called the Recruitment Model. The Recruitment model utilises the "recruitment" principle known to exist in motor pools and applies this distributed processing methodology to the higher levels of motor action to explain how complex structures similar to the human skeletal system might be controlled. A simple version of the Recruitment Model is simulated showing an animation of a running "stick man". This simulation demonstrates some of the principles necessary to solve problems relating to synergy formation

A multimedia website for the Battle of Gettysburg

This thesis explains the development of a website for eighth graders about the Battle of Gettysburg. One purpose of the project is to provide several primary source documents, pictures, video from a reenactment of the Battle of Gettysburg, clips from movies about the Civil War, and other material that suppport the students in their learning. The second purpose is to fulffill standard 8.10 of History-Social Science Content Standards for eight grade. This project will help students fulfill this requirement

Analysis of pp → ππ Data at Low Energy and its Implications

This thesis is a study of data on pp → ππ in the range 0.36 ≤ P(_lab) ≤ 1.55 GeV/c taken by the PS 172 experiment at CERN's LEAR facility. The aim is to elucidate the nature of mesonic states coupling both to baryon-antibaryon and meson-meson channels. The PS 172 data are compared with, and found to be consistent with, earlier data on the same channel, and, in a model independent way, the consistency of the PS 172 results with BNL data on pp pp → π(^0)π(^0) is also established. The first amplitude analysis of pp → π(^0)π(^0) to incorporate the PS 172 data is performed and it is found that from the hundreds of possible amplitudes, only two are compatible with the BNL pp → π(^0)π(^0) data and with threshold conditions. The latter may be applied in a far more rigorous way than has been previously possible since the PS 172 momentum range extends so close to threshold. Both of the solutions found exhibit resonances with spins 0-5 and the masses, widths and couplings of these states are deduced. The lowest spin resonances are found to have such large couplings to NN that they are unlikely to be simple qq states

Female impersonation as an alternative reproductive strategy in giant cuttlefish

Out of all the animals, cephalopods possess an unrivalled ability to change their shape and body patterns. Our observations of giant cuttlefish (Sepia apama) suggest this ability has allowed them to evolve alternative mating strategies in which males can switch between the appearance of a female and that of a male in order to foil the guarding attempts of larger males. At a mass breeding aggregation in South Australia, we repeatedly observed single small males accompanying mating pairs. While doing so, the small male assumed the body shape and patterns of a female. Such males were never attacked by the larger mate-guarding male. On more than 20 occasions, when the larger male was distracted by another male intruder, these small males, previously indistinguishable from a female, were observed to change body pattern and behaviour to that of a male in mating display. These small males then attempted to mate with the female, often with success. This potential for dynamic sexual mimicry may have played a part in driving the evolution of the remarkable powers of colour and shape transformation which characterize the cephalopods