A contextual approach to the study of faunal assemblages from Lower and Middle Palaeolithic sites in the UK

This thesis represents a site-specific, holistic analysis of faunal assemblage formation at four key Palaeolithic sites (Boxgrove, Swanscombe, Hoxne and Lynford). Principally this research tests the a priori assumption that lithic tools and modified large to medium-sized fauna recovered from Pleistocene deposits represent a cultural accumulation and direct evidence of past hominin meat-procurement behaviour. Frequently, the association of lithics and modified fauna at a site has been used to support either active large-mammal hunting by hominins or a scavenging strategy. Hominin bone surface modification (cut marks, deliberate fracturing) highlight an input at the site but cannot be used in isolation from all other taphonomic modifiers as evidence for cultural accumulation. To understand the role of hominins in faunal assemblage accumulation all other taphonomic factors at a site must first be considered. A site-specific framework was established by using data on the depositional environment and palaeoecology. This provided a context for the primary zooarchaeological data (faunal material: all elements and bone surface modification) and helped explain the impact and importance of faunal accumulators and modifiers identified during analysis. This data was synthesized with information on predator and prey behavioural ecology to assess potential conflict and competition within the site palaeoenvironment. Results indicate that association of lithics and modified fauna are not sufficient evidence of a cultural accumulation; two sites (Swanscombe, Hoxne) demonstrate evidence of fluvial accumulation and disturbance. Whereas at Boxgrove, hominins had primary access to all fauna, fully exploiting carcasses. At Lynford, the mammoth remains were not modified by hominins, whilst other species only indicated exploitation for marrow, which conflicts with existing interpretations. I argue that hunting and scavenging are a continuum of behaviour, not necessarily represented at each site

FGF/heparin differentially regulates Schwann cell and olfactory ensheathing cell interactions with astrocytes: a role in astrocytosis

After injury, the CNS undergoes an astrocyte stress response characterized by reactive astrocytosis/proliferation, boundary formation, and increased glial fibrillary acidic protein (GFAP) and chondroitin sulfate proteoglycan (CSPG) expression. Previously, we showed that in vitro astrocytes exhibit this stress response when in contact with Schwann cells but not olfactory ensheathing cells (OECs). In this study, we confirm this finding in vivo by demonstrating that astrocytes mingle with OECs but not Schwann cells after injection into normal spinal cord. We show that Schwann cell-conditioned media (SCM) induces proliferation in monocultures of astrocytes and increases CSPG expression in a fibroblast growth factor receptor 1 (FGFR1)-independent manner. However, SCM added to OEC/astrocyte cocultures induces reactive astrocytosis and boundary formation, which, although sensitive to FGFR1 inhibition, was not induced by FGF2 alone. Addition of heparin to OEC/astrocyte cultures induces boundary formation, whereas heparinase or chlorate treatment of Schwann cell/astrocyte cultures reduces it, suggesting that heparan sulfate proteoglycans (HSPGs) are modulating this activity. In vivo, FGF2 and FGFR1 immunoreactivity was increased over grafted OECs and Schwann cells compared with the surrounding tissue, and HSPG immunoreactivity is increased over reactive astrocytes bordering the Schwann cell graft. These data suggest that components of the astrocyte stress response, including boundary formation, astrocyte hypertrophy, and GFAP expression, are mediated by an FGF family member, whereas proliferation and CSPG expression are not. Furthermore, after cell transplantation, HSPGs may be important for mediating the stress response in astrocytes via FGF2. Identification of factors secreted by Schwann cells that induce this negative response in astrocytes would further our ability to manipulate the inhibitory environment induced after injury to promote regeneration

Computationally efficient velocity profile solutions for cardiac haemodynamics

DOI: 10.1109/IEMBS.2004.1403316This paper reformulates the non-linear differential equations associated with time varying resistance in minimal cardio-vascular system models into a system of linear equations with an analytical solution. The importance of including time varying resistance is shown for a single chamber model where there is a 17.5% difference in cardiac output when compared with a constant resistance model. However, the increased complexity has significant extra computational cost. This new formulation provides a significant computational saving of 15x over the previous method. This improvement enables more physiological accuracy with minimal cost in computational time. As a result, the model can be used in clinical situations to aid diagnosis and therapy selection without compromising on physiological accuracy

Perturbative spectrum of Trapped Weakly Interacting Bosons in Two Dimensions

We study a trapped Bose-Einstein condensate under rotation in the limit of weak, translational and rotational invariant two-particle interactions. We use the perturbation-theory approach (the large-N expansion) to calculate the ground-state energy and the excitation spectrum in the asymptotic limit where the total number of particles N goes to infinity while keeping the total angular momentum L finite. Calculating the probabilities of different configurations of angular momentum in the exact eigenstates gives us a clear view of the physical content of excitations. We briefly discuss the case of repulsive contact interaction.Comment: Revtex, 10 pages, 1 table, to appear in Phys. Rev.

Improving the decision usefulness of the corporate annual report

Shareholder surveys consistently demonstrate users' perceptions of the importance of annual report disclosures in the decision-making process and their readership of the Chairman's narrative. - Yet existing empirical evidence casts doubt on the informational content of any part of the annual report. This study offers a partial explanation of this anomaly by demonstrating the decision usefulness of annual report disclosures, focusing on improvements made possible by a more detailed analysis of the content and its presentation. The Chairman's narrative provides a voluntary disclosure acting as a vehicle for signalling the intentions of the executive, but also as an opportunity to convey information incremental to the financial statements. The absence of a shared meaning for accounting terms between the users and preparers of the, accounts provides a further opportunity for miscommunication. and misinformation. Such differences may be attributable to either the complexity of content or the complexity of presentation. Both are addressed in this study. With regard to content, the study examines the environmental predictability of the semantic content by constructing explanatory models of the financial performance of the enterprise. With regard to presentation, both the readability and cognisability of the narrative are evaluated with reference to the size and financial performance of the enterprise. The study concludes with an examination of alternative methods for the presentation of financial information, focusing on the use of schematic faces as a potentially unique format with specific portrayal advantages. The facial format is shown to be an efficient method of processing, producing decisions of comparable quality to those with financial statement information, and in a much shorter time. An approach is adopted which rectifies the deficiencies of earlier studies by incorporating the full force of the existing psychological evidence and by generating an optimum feature assignment experimentally

Integrated electrical and mechanical modelling of integrated-full-electric-propulsion systems

Integrated Full Electric Propulsion (IFEP) systems are the subject of much interest at present. Current research is focused on analysing and improving aspects of subsystem and system performance. However, there is a great need to look more widely at the `multi-physics' problem of characterising the dynamic interactions between the electrical and mechanical systems. This paper will discuss the changing nature of modelling and simulation to aid research into IFEP systems, outlining the alternative angle taken by the Advanced Marine Electrical Propulsion Systems (AMEPS) project to characterise and investigate electrical-mechanical system interactions. The paper will describe this approach and highlight the unique challenges associated with the problem, discussing the suitable methods that will be adopted to address these challenges. Finally, an overview of the present and future research opportunities facilitated via the AMEPS project will be presented

Template coexistence in prebiotic vesicle models

The coexistence of distinct templates is a common feature of the diverse proposals advanced to resolve the information crisis of prebiotic evolution. However, achieving robust template coexistence turned out to be such a difficult demand that only a class of models, the so-called package models, seems to have met it so far. Here we apply Wright's Island formulation of group selection to study the conditions for the coexistence of two distinct template types confined in packages (vesicles) of finite capacity. In particular, we show how selection acting at the level of the vesicles can neutralize the pressures towards the fixation of any one of the template types (random drift) and of the type with higher replication rate (deterministic competition). We give emphasis to the role of the distinct generation times of templates and vesicles as yet another obstacle to coexistence.Comment: 7 pages, 8 figure

Thermo-Mechanical Processing Parameters for the INCONEL ALLOY 740

In 2000, a Cooperative Research and Development Agreement (CRADA) was undertaken between the Oak Ridge National Laboratory (ORNL) and the Special Metals Corporation (SMC) to determine the mechanical property response of the IN740 alloy to help establish thermo-mechanical processing parameters for the use of this alloy in supercritical and ultra-critical boiler tubes with the potential for other end uses. SMC had developed an alloy, commercially known as INCONEL alloy 740, which exhibited various beneficial physical, mechanical, and chemical properties. As part of SMC's on-going efforts to optimize this alloy for targeted boiler applications there was a need to develop an understanding of the thermo-mechanical response of the material, characterize the resulting microstructure from this processing, and possibly, utilize models to develop the appropriate processing scheme for this product