title: Evaluation of a sudden brake warning system: Effect on the response time of the following driver

authors: Isler, Robert B.

subjects: driving

abstract: This study used a video-based braking simulation dual task to carry out a preliminary evaluation of the effect of a sudden brake warning system (SBWS) in a leading passenger vehicle on the response time of the following driver. The primary task required the participants (N = 25, 16 females, full NZ license holders) to respond to sudden braking manoeuvres of a lead vehicle during day and night driving, wet and dry conditions and in rural and urban traffic, while concurrently performing a secondary tracking task using a computer mouse. The SBWS in the lead vehicle consisted of g-force controlled activation of the rear hazard lights (the rear indicators flashed), in addition to the standard brake lights. Overall, the results revealed that responses to the braking manoeuvres of the leading vehicles when the hazard lights were activated by the warning system were 0.34 s (19%) faster compared to the standard brake lights. The SBWS was particularly effective when the simulated braking scenario of the leading vehicle did not require an immediate and abrupt braking response. Given this, the SBWS may also be beneficial for allowing smoother deceleration, thus reducing fuel consumption. These preliminary findings justify a larger, more ecologically valid laboratory evaluation which may lead to a naturalistic study in order to test this new technology in ‘real world’ braking situations.

text: Evaluation of a sudden brake warning system: Effect on the response time of the following driver This study used a video-based braking simulation dual task to carry out a preliminary evaluation of the effect of a sudden brake warning system (SBWS) in a leading passenger vehicle on the response time of the following driver. The primary task required the participants (N = 25, 16 females, full NZ license holders) to respond to sudden braking manoeuvres of a lead vehicle during day and night driving, wet and dry conditions and in rural and urban traffic, while concurrently performing a secondary tracking task using a computer mouse. The SBWS in the lead vehicle consisted of g-force controlled activation of the rear hazard lights (the rear indicators flashed), in addition to the standard brake lights. Overall, the results revealed that responses to the braking manoeuvres of the leading vehicles when the hazard lights were activated by the warning system were 0.34 s (19%) faster compared to the standard brake lights. The SBWS was particularly effective when the simulated braking scenario of the leading vehicle did not require an immediate and abrupt braking response. Given this, the SBWS may also be beneficial for allowing smoother deceleration, thus reducing fuel consumption. These preliminary findings justify a larger, more ecologically valid laboratory evaluation which may lead to a naturalistic study in order to test this new technology in ‘real world’ braking situations.

year: 2010

title: Modelling single cell electroporation with bipolar pulse: Simulating dependance of electroporated fractional pore area on the bipolar field frequency

authors: Talele, Sadhana

subjects: electroporation

abstract: Electroporation EP, in which external electric field pulses create transient pores in a cell membrane, is an important technique for delivery of DNA and drugs into the cell. To enable entry of DNA into cells, the pores should have sufficiently large radii, remain open long enough for the DNA chain to enter the cell, and should not cause membrane rupture. A numerical model for a single spherical cell electroporated by application of direct and/or alternating external electric field pulses has been developed. The model is used to calculate the transmembrane potential, the number of pores and the the fraction of area occupied by the pores (fractional pore area FPA) in response to the various electric field pulses. Presented here are simulation results used to compare the extent of electroporation (fractional pore area FPA) in response to eletric field pulses of different frequencies in a range of extracellular conductivity for two cell raii. It is also observed that a 1 MHz bipolar sinusoidal applied electric field pulse reduces the relative difference in fractional pore area between the two cell sizes compared to a 100 kHz pulse.

text: Modelling single cell electroporation with bipolar pulse: Simulating dependance of electroporated fractional pore area on the bipolar field frequency Electroporation EP, in which external electric field pulses create transient pores in a cell membrane, is an important technique for delivery of DNA and drugs into the cell. To enable entry of DNA into cells, the pores should have sufficiently large radii, remain open long enough for the DNA chain to enter the cell, and should not cause membrane rupture. A numerical model for a single spherical cell electroporated by application of direct and/or alternating external electric field pulses has been developed. The model is used to calculate the transmembrane potential, the number of pores and the the fraction of area occupied by the pores (fractional pore area FPA) in response to the various electric field pulses. Presented here are simulation results used to compare the extent of electroporation (fractional pore area FPA) in response to eletric field pulses of different frequencies in a range of extracellular conductivity for two cell raii. It is also observed that a 1 MHz bipolar sinusoidal applied electric field pulse reduces the relative difference in fractional pore area between the two cell sizes compared to a 100 kHz pulse.

year: 2010

title: Addressing the context and complexity of indigenous language revitalization

authors: May, Stephen

subjects: revitilization

abstract: This response discusses six key themes that emerge, either explicitly or implicitly, from Nancy Hornberger's exemplary analysis of the challenges facing indigenous language revitalization initiatives, particularly as they are currently expressed and implemented in three key indigenous language education contexts--Quechua in the South American Andes; Guarani in Paraguay and Maori in Aotearoa/New Zealand. These themes include, first, the importance of recognizing the wider social and political contexts within which indigenous revitalization initiatives are invariably situated. Second, it requires a related recognition of the internationalism of these initiatives. Third, any academic analysis of indigenous language revitalization requires, or at least must benefit from, an interdisciplinary approach, as exemplified by Hornberger's own analysis. Fourth, Hornberger's continua of biliteracy provides a sufficiently robust framework to explore the complexities and interrelationships inevitably involved in the articulation of language revitalization efforts, as well as how individuals and groups are situated in relation to those efforts. Fifth, the ongoing challenges and tensions inherent in indigenous language revitalization efforts need to continue to be discussed candidly, in order for them to be seriously addressed and, where possible, resolved. And finally, the importance of recognizing and including the voices of those centrally involved in these initiatives, as Hornberger again does, is a crucial feature, as well as a reflection of the inclusive, emancipatory aims of indigenous language revitalization itself.

text: Addressing the context and complexity of indigenous language revitalization This response discusses six key themes that emerge, either explicitly or implicitly, from Nancy Hornberger's exemplary analysis of the challenges facing indigenous language revitalization initiatives, particularly as they are currently expressed and implemented in three key indigenous language education contexts--Quechua in the South American Andes; Guarani in Paraguay and Maori in Aotearoa/New Zealand. These themes include, first, the importance of recognizing the wider social and political contexts within which indigenous revitalization initiatives are invariably situated. Second, it requires a related recognition of the internationalism of these initiatives. Third, any academic analysis of indigenous language revitalization requires, or at least must benefit from, an interdisciplinary approach, as exemplified by Hornberger's own analysis. Fourth, Hornberger's continua of biliteracy provides a sufficiently robust framework to explore the complexities and interrelationships inevitably involved in the articulation of language revitalization efforts, as well as how individuals and groups are situated in relation to those efforts. Fifth, the ongoing challenges and tensions inherent in indigenous language revitalization efforts need to continue to be discussed candidly, in order for them to be seriously addressed and, where possible, resolved. And finally, the importance of recognizing and including the voices of those centrally involved in these initiatives, as Hornberger again does, is a crucial feature, as well as a reflection of the inclusive, emancipatory aims of indigenous language revitalization itself.

year: 2006-01-01