title: Temperature and timescale dependence of protein dynamics in methanol : water mixtures

authors: Tournier, Alexander L.

subjects: hydrated proteins

abstract: Experimental and computer simulation studies have suggested the presence of a transition in the dynamics of hydrated proteins at around 180–220 K. This transition is manifested by nonlinear behaviour in the temperature dependence of the average atomic mean-square displacement which increases at high temperature. Here, we present results of a dynamic neutron scattering analysis of the transition for a simple enzyme: xylanase in water : methanol solutions of varying methanol concentrations. In order to investigate motions on different timescales, two different instruments were used: one sensitive to  100 ps timescale motions and the other to  ns timescale motions. The results reveal distinctly different behaviour on the two timescales examined. On the shorter timescale the dynamics are dictated by the properties of the surrounding solvent: the temperature of the dynamical transition lowers with increasing methanol concentration closely following the melting behaviour of the corresponding water : methanol solution. This contrasts with the longer (ns) timescale results in which the dynamical transition appears at temperatures lower than the corresponding melting point of the cryosolvent. These results are suggested to arise from a collaborative effect between the protein surface and the solvent which lowers the effective melting temperature of the protein hydration layer. Taken together, the results suggest that the protein solvation shell may play a major role in the temperature dependence of protein solution dynamics.

text: Temperature and timescale dependence of protein dynamics in methanol : water mixtures Experimental and computer simulation studies have suggested the presence of a transition in the dynamics of hydrated proteins at around 180–220 K. This transition is manifested by nonlinear behaviour in the temperature dependence of the average atomic mean-square displacement which increases at high temperature. Here, we present results of a dynamic neutron scattering analysis of the transition for a simple enzyme: xylanase in water : methanol solutions of varying methanol concentrations. In order to investigate motions on different timescales, two different instruments were used: one sensitive to  100 ps timescale motions and the other to  ns timescale motions. The results reveal distinctly different behaviour on the two timescales examined. On the shorter timescale the dynamics are dictated by the properties of the surrounding solvent: the temperature of the dynamical transition lowers with increasing methanol concentration closely following the melting behaviour of the corresponding water : methanol solution. This contrasts with the longer (ns) timescale results in which the dynamical transition appears at temperatures lower than the corresponding melting point of the cryosolvent. These results are suggested to arise from a collaborative effect between the protein surface and the solvent which lowers the effective melting temperature of the protein hydration layer. Taken together, the results suggest that the protein solvation shell may play a major role in the temperature dependence of protein solution dynamics.

year: 2005

title: Radiocarbon determinations from the Mulifanua Lapita site, Upolu, western Samoa

authors: Petchey, Fiona

subjects: Mulifanua

abstract: The Mulifanua ferry berth has the distinction of being the only site in Samoa with dentate-stamped Lapita wares, and is the most easterly Lapita site in the Pacific. Two new radiocarbon determinations of material associated with Lapita pottery found at Mulifanua are presented. The accuracy of this data is evaluated according to the results of recent reassessment of pottery from the site, and current theories regarding the age of Lapita settlement in the eastern Pacific. The resulting calibrated radiocarbon ages put occupation of the Mulifanua Lapita site at around 2880-2750 cal BP (930–800 BC). This conclusion is in agreement with the pottery chronology and supports recent hypotheses of rapid Lapita settlement in the Fiji/Tonga region around 2850–2700 cal BP (900–750 BC).

text: Radiocarbon determinations from the Mulifanua Lapita site, Upolu, western Samoa The Mulifanua ferry berth has the distinction of being the only site in Samoa with dentate-stamped Lapita wares, and is the most easterly Lapita site in the Pacific. Two new radiocarbon determinations of material associated with Lapita pottery found at Mulifanua are presented. The accuracy of this data is evaluated according to the results of recent reassessment of pottery from the site, and current theories regarding the age of Lapita settlement in the eastern Pacific. The resulting calibrated radiocarbon ages put occupation of the Mulifanua Lapita site at around 2880-2750 cal BP (930–800 BC). This conclusion is in agreement with the pottery chronology and supports recent hypotheses of rapid Lapita settlement in the Fiji/Tonga region around 2850–2700 cal BP (900–750 BC).

year: 2001

title: Software development: Involving Tangata Whenua and incorporating Tikanga Māori

authors: Taia, Ivy

subjects: software engineering

abstract: Over the past fifty years, software development (SD) has been dominated by Western approaches, which is widely accepted as the standard way of doing things (Diaz Andrade et al., 2021). Consequently, many software applications for specific Indigenous cultures, especially health interventions and educational software (Dobson, Whittaker, Bartley, Connor, Chen, Ross & McCool, 2017; Fleer, 1989), were developed using traditional software engineering (SE) methodologies. Although these methodologies provide the workflows and methods for developing software, they do not provide guidelines for developing Indigenous software. While there have been numerous studies on diversity, such as gender and ethnicity in the field of Information Systems, there is very little research on the practices of involving Indigenous people and incorporating their traditional customs in the software development process. This thesis examines the participation of Indigenous people in software development. The research specifically focuses on Tangata Whenua (Māori people, the Indigenous population of Aotearoa New Zealand) and Tikanga Māori (Māori cultural methods). Our findings are useful to those attempting to enhance Indigenous representation in software development, especially those wanting to involve Māori people and their cultural methods in the development process and design of software.

text: Software development: Involving Tangata Whenua and incorporating Tikanga Māori Over the past fifty years, software development (SD) has been dominated by Western approaches, which is widely accepted as the standard way of doing things (Diaz Andrade et al., 2021). Consequently, many software applications for specific Indigenous cultures, especially health interventions and educational software (Dobson, Whittaker, Bartley, Connor, Chen, Ross & McCool, 2017; Fleer, 1989), were developed using traditional software engineering (SE) methodologies. Although these methodologies provide the workflows and methods for developing software, they do not provide guidelines for developing Indigenous software. While there have been numerous studies on diversity, such as gender and ethnicity in the field of Information Systems, there is very little research on the practices of involving Indigenous people and incorporating their traditional customs in the software development process. This thesis examines the participation of Indigenous people in software development. The research specifically focuses on Tangata Whenua (Māori people, the Indigenous population of Aotearoa New Zealand) and Tikanga Māori (Māori cultural methods). Our findings are useful to those attempting to enhance Indigenous representation in software development, especially those wanting to involve Māori people and their cultural methods in the development process and design of software.

year: 2025