Feeding selectivity of brown trout (Salmo trutta) in Loch Ness, Scotland

The aim of this study was to compare statistically the zooplankton assemblage ingested by brown trout (Salmo trutta) in Loch Ness with that of the zooplankton in the water column. This would allow the examination of the apparent paradox that very few copepods appear to be consumed by trout at a time of year when they are numerous and readily available as food. The investigation was limited to the crustacean zooplankters, since the Rotifera are generally so small that they are only of interest to fish in the first few days of life. 25 trout were obtained from anglers, and the stomach contents of non-"ferox" animals analysed. Samples of pelagic zooplankton were obtained approximately monthly from 30-m vertical net-hauls (mesh size 100 km). It is concluded that the variation in dietary composition with trout wet weight indicates an ontogenetic habitat shift producing spatial separation of young and older individuals

Variability in Plio-Pleistocene climates, habitats, and ungulate biomass in southern Africa

Vrba, and deMenocal and Bloemendal have emphasised the importance of climatic change, particularly temperature, in the context of evolution on the African continent within the past 5 million years. There is no doubt that long-term changes in climate would have affected African habitats, which in turn would have affected the distribution and abundance of populations of various mammalian taxa, including ungulates and hominids. In this study we explore relationships between oxygen isotope ratios (as determined from Shackleton's analysis of foraminifera from deep-sea cores), and estimates of ungulate biomass as determined from faunal assemblages from Plio-Pleistocene sites in southern Africa, using an approach outlined previously. We go further to assess temporal variability in ungulate biomass in terms of changes in habitat, gene pools and hominid evolutio

A new conceptual framework for the evaluation of L&D programmes

The evaluation of learning and development programmes is one of the most important processes for the L&D function as it determines functional credibility by the creation of value from the L&D budget. The Kirkpatrick (1954) framework has primacy in the world of evaluation along with a small number of other frameworks, e.g. Phillips (1999), Holton (2000) Brinkerhoff (2003). However, despite its acknowledged ineffectiveness, efforts to replace the framework have been unsuccessful, becoming the prevailing paradigm for evaluation which could be an increasing risk for L&D itself in proving legitimacy and credibility. A review of wider literature reveals new opportunities to synthesise different theoretical positions to build a new framework that could add value to practice, particularly by using Decision Theory, Hubbard (2007), Forecasting, Armstrong (2001) and ‘Intention’ Anscombe (1959). This study adds to the literature by highlighting opportunities from that synthesis for further research and for practice. The researcher is a specialist and experienced evaluator of L&D programmes and functions with access to a wide range of practitioners and organisations willing to help with research. This research investigates attitudes and current practice in evaluation and, using new technologies and the synthesis of ideas and methods, to posit a new evaluation framework. This framework builds an evaluation strategy using forecasting methods with the Central Limit Theorum as the key drivers in its evaluation ‘mix’ to generate highly accurate outputs. The framework has a subset of Quadrants that generate the evaluation outcomes and one specific Quadrant is the subject of this research, assessed using a Case Study approach to be shown to have potential impact for L&D. The findings from the research show that this new framework can deliver evaluation outputs with targeted levels of accuracy for a fraction of the cost, time and resource required by the traditional summative methods, currently used as part of the existing evaluation paradigm. Whether this approach can rival the prevailing paradigm will be for practitioners to decide and is outside the scope of this research but it is suggested that it could offer a real choice for L&D evaluators

Doctor of Philosophy

dissertationLow back (LBP) pain is common and represents a significant societal burden due to costs associated with lost work productivity and medical care. LBP presenting with leg pain, or lumbosacral radicular syndrome (LRS), worsens prognosis and increases disability and cost. Recovery from LBP is highly variable. Improving our understanding of recovery after acute LBP provides an opportunity to change the course of symptoms. Recent studies have identified distinct recovery patterns among patients with LBP. These are generally represented by recovery, moderate persisting pain, high persisting pain, or recurrence. In a cohort of workers with incident LBP, we examined the presence of these patterns. Using pain scores from monthly follow-up visits over the course of 1 year, we characterized recovery. A growth mixture model identified four distinct trajectories consistent with previous literature with distributions favoring recovery. The four classes were identified as recovered (60%), moderate persisting pain (28%), high persisting pain (8%) and recurrent pain (4%). The presence of leg pain increased pain intensity, slowed recovery, and increased the likelihood of being in the high persisting pain class. We further characterized these classes by examining the association between baseline covariates and class status using logistic regression. Moderate persisting pain and high persisting pain was more prevalent among Hispanic workers and those reporting more severe prior low back pain. Additionally, high lifting demands and low social iv support from coworkers was associated with moderate persisting pain. Workers with LRS were twice as likely to have high persisting pain even after adjusting for race and low back pain history (adjusted OR 2.7 (1.4, 5.4)). Finally, in a nationally representative cohort from the SPORT population, we examined nonsurgical treatments utilized in managing patients with persisting symptoms of LRS who seek secondary care but do not elect surgical management. The primary nonsurgical interventions used were medication, spinal injections, and physical therapy. Higher baseline disability, the presence of neurologic deficit, and patient preference for physical therapy were all factors associated with receiving physical therapy as an initial management strategy. Patients receiving physical therapy within the first 6 weeks did not demonstrate any significant differences in primary outcomes of pain and disability compared to those who did not receive physical therapy. Recovery from LBP is highly variable but seems to be described by four distinct patterns of pain. Individuals with low back-related leg pain (LRS) have increased odds of a poor recovery. For patients with persistent LRS, there is significant variation and complexity in nonsurgical management decisions without clear benefit in clinical outcomes. There remains a need to identify optimal management strategies and sequencing of treatment for this population

Twenty Golden Years of Battery R&D at CSIR,1974–1994

This paper is a personal reflection of 20 years of sodium- and lithium-based battery R&D in South Africa between 1974 and 1994. The impact of the innovative materials science and engineering research conducted during this period is highlighted by the later successful implementation of batteries in powering practical systems, as well as in technology licensing.Keywords: CSIR, battery, Zebra, sodium-metal chloride, sodium-sulphur, LiAl/FeSx, lithium-ion, spine

Comparison of Holocene temperature data (Boomplaas Cave) and oxygen isotope data (Cango Caves)

NCS201

The Piltdown case: Further questions

NCS201

The possibility of lichen growth on bones of Homo naledi: Were they exposed to light?

NCS201

Carnivore activity at Klasies River Mouth: a response to Binford

Environmental and behavioural factors contributed to variability in the relative abundance of Raphicerus (grysbok/steenbok) represented in Late Pleistocene and Holocene deposits at the complex of caves at Klasies River Mouth and at Nelson Bay Cave in the southern Cape Province, South Africa. Binford has used the relative abundance of Raphicerus in an index assumed to measure the degree of hunting by Middle Stone Age hominids. However, the occurrence of relatively high numbers of Raphicerus with leopards and baboons in some layers is likely to have been associated, at least in part, with leopard activity, particularly at times when relatively large ungulates were not common in the palaeoenvironment and when the cave sites were not frequently occupied by hominids with control over fire. Binford's indices are re-assessed in the light of other indices which are designed to identify assemblages that have a relatively high probability of having been accumulated by leopards and/or other carnivores