title: Fatigue, work-rest cycles, and psychomotor performance of New Zealand truck drivers

authors: Charlton, Samuel G.

subjects: New Zealand

abstract: The goal of the present research programme was to find out how common driver fatigue is among New Zealand truck drivers and the degree to which they suffer from fatigue-related effects on their driving performance. To that end, 606 truck drivers were tested at a variety of sites throughout the North Island of New Zealand. The results showed that a considerable number of drivers are operating in excess of the hours of service regulations. The three fatigue measures in our survey indicated that there are significant levels of fatigue in the New Zealand transport industry. One out of four of the drivers' self-ratings of fatigue were in the "tired" range, even though many of them were surveyed at the beginning of their shift. A psychomotor test also indicated a very high level of fatigue in the sample. Overall, 24% of the sample failed the psychomotor performance criteria. Amount of rest and sleep, shift length, and number of driving days per week were all significantly related to psychomotor performance. The results of the daytime sleepiness inventory showed that the drivers in our sample had somewhat higher levels of daytime sleepiness than do heavy goods vehicle drivers in Great Britain. There was significant correspondence between drivers' self-ratings, psychomotor performance, and daytime sleepiness fatigue measures.

text: Fatigue, work-rest cycles, and psychomotor performance of New Zealand truck drivers The goal of the present research programme was to find out how common driver fatigue is among New Zealand truck drivers and the degree to which they suffer from fatigue-related effects on their driving performance. To that end, 606 truck drivers were tested at a variety of sites throughout the North Island of New Zealand. The results showed that a considerable number of drivers are operating in excess of the hours of service regulations. The three fatigue measures in our survey indicated that there are significant levels of fatigue in the New Zealand transport industry. One out of four of the drivers' self-ratings of fatigue were in the "tired" range, even though many of them were surveyed at the beginning of their shift. A psychomotor test also indicated a very high level of fatigue in the sample. Overall, 24% of the sample failed the psychomotor performance criteria. Amount of rest and sleep, shift length, and number of driving days per week were all significantly related to psychomotor performance. The results of the daytime sleepiness inventory showed that the drivers in our sample had somewhat higher levels of daytime sleepiness than do heavy goods vehicle drivers in Great Britain. There was significant correspondence between drivers' self-ratings, psychomotor performance, and daytime sleepiness fatigue measures.

year: 2006

title: Testing Macromolecular Rate Theory

authors: Kraakman, Kirsty Leigh

subjects: enzymes

abstract: Enzymatic rate increase with respect to temperature has widely been described by transition-state theory. The experimentally observed rate decline above an optimum temperature (Tₒₚₜ) for enzymes has previously been attributed to thermal denaturation, despite the known discrepancies with this rationalisation. Recently, a new model has been proposed to describe the temperature dependence of enzymatic rates: macromolecular rate theory (MMRT). This new theory incorporates heat capacity into the rate equation to provide a more robust thermodynamic description of rates, and account for the distinct curvature seen in biological temperature-rate profiles. The current study explores the effect of enzyme vibrational modes on heat capacity, and how alterations to the distribution of these modes, by heavy isotope substitution, affect the change in heat capacity along the reaction coordinate. The results presented show clear evidence for the role of vibrational mode frequency distributions in governing the curvature of temperature-rate profiles, and present a hypothesis for how this shift differs for the enzyme-substrate complex and the enzyme-transition state complex. The study also addresses the ability of MMRT to accurately model enzymatic rates over a wide temperature range for two different enzymes. As a result of this study, a new MMRT equation was generated to include a temperature dependence term for the heat capacity, a factor previously considered negligible. The data generated has shown that heat capacity is temperature dependent and this is a significant factor in accurately describing enzymatic rates with respect to temperature. In particular, for complex enzymatic reactions whose enthalpy distribution is significantly narrowed over the reaction co-ordinate. These findings have helped to develop MMRT to provide more accurate descriptions of a broader range of data. Additionally, the conclusions regarding vibrational mode distribution provide insight into the physical basis for heat capacity changes over the course of the enzymatic reaction. Investigation of the hypotheses generated from this research will offer further insight into the mechanistic contributions of vibrational modes and heat capacity in enzyme catalysis.

text: Testing Macromolecular Rate Theory Enzymatic rate increase with respect to temperature has widely been described by transition-state theory. The experimentally observed rate decline above an optimum temperature (Tₒₚₜ) for enzymes has previously been attributed to thermal denaturation, despite the known discrepancies with this rationalisation. Recently, a new model has been proposed to describe the temperature dependence of enzymatic rates: macromolecular rate theory (MMRT). This new theory incorporates heat capacity into the rate equation to provide a more robust thermodynamic description of rates, and account for the distinct curvature seen in biological temperature-rate profiles. The current study explores the effect of enzyme vibrational modes on heat capacity, and how alterations to the distribution of these modes, by heavy isotope substitution, affect the change in heat capacity along the reaction coordinate. The results presented show clear evidence for the role of vibrational mode frequency distributions in governing the curvature of temperature-rate profiles, and present a hypothesis for how this shift differs for the enzyme-substrate complex and the enzyme-transition state complex. The study also addresses the ability of MMRT to accurately model enzymatic rates over a wide temperature range for two different enzymes. As a result of this study, a new MMRT equation was generated to include a temperature dependence term for the heat capacity, a factor previously considered negligible. The data generated has shown that heat capacity is temperature dependent and this is a significant factor in accurately describing enzymatic rates with respect to temperature. In particular, for complex enzymatic reactions whose enthalpy distribution is significantly narrowed over the reaction co-ordinate. These findings have helped to develop MMRT to provide more accurate descriptions of a broader range of data. Additionally, the conclusions regarding vibrational mode distribution provide insight into the physical basis for heat capacity changes over the course of the enzymatic reaction. Investigation of the hypotheses generated from this research will offer further insight into the mechanistic contributions of vibrational modes and heat capacity in enzyme catalysis.

year: 2017

title: Inter-propositional semantic relations and semantic relational encoding in written discourse in Maori: an investigation

authors: Houia, Waldo

subjects: Maori

abstract: This thesis is an investigation of the various ways in which relationships of meaning between propositions (such as reason-result and temporal overlap) are encoded (as clauses, sentences and groups of sentences) and signalled in Maori.
In Chapter 1, the overall research topic and research questions are outlined.
Chapter 2 locates the research on inter-propositional semantic relations with reference to the concept of cohesion which is central to inter-propositional relational signalling and encoding. Here, reference is made to a number of relevant publications in the area.
Chapter 3 provides an introductory examination of the role of cohesion in the encoding and signalling of inter-propositional semantic relations in Maori.
Chapter 4 introduces a corpus of written texts and examines that corpus in terms of the ways in which inter-propositional semantic relations are encoded.
Chapter 5 examines a number of textbooks designed for learners of both English and Maori in terms of the extent to which they draw upon insights relating to the operation of inter-propositional semantic relations.
In Chapter 6, the research findings are summarised and their implications for aspects of the teaching and learning of Maori are discussed. In addition, suggestions are made in relation to future research possibilities.
Overall, the conclusion reached is that the study of semantic relational encoding and signalling in Maori texts reveals a number of aspects of language that appear not to be commonly taught and suggests the need for further studies of this type.

text: Inter-propositional semantic relations and semantic relational encoding in written discourse in Maori: an investigation This thesis is an investigation of the various ways in which relationships of meaning between propositions (such as reason-result and temporal overlap) are encoded (as clauses, sentences and groups of sentences) and signalled in Maori.
In Chapter 1, the overall research topic and research questions are outlined.
Chapter 2 locates the research on inter-propositional semantic relations with reference to the concept of cohesion which is central to inter-propositional relational signalling and encoding. Here, reference is made to a number of relevant publications in the area.
Chapter 3 provides an introductory examination of the role of cohesion in the encoding and signalling of inter-propositional semantic relations in Maori.
Chapter 4 introduces a corpus of written texts and examines that corpus in terms of the ways in which inter-propositional semantic relations are encoded.
Chapter 5 examines a number of textbooks designed for learners of both English and Maori in terms of the extent to which they draw upon insights relating to the operation of inter-propositional semantic relations.
In Chapter 6, the research findings are summarised and their implications for aspects of the teaching and learning of Maori are discussed. In addition, suggestions are made in relation to future research possibilities.
Overall, the conclusion reached is that the study of semantic relational encoding and signalling in Maori texts reveals a number of aspects of language that appear not to be commonly taught and suggests the need for further studies of this type.

year: 2001