title: Improving road safety and health: Understandng kava's impact on driver fitness.

authors: Aporosa, S. 'Apo'

abstract: Kava (Piper methysticum) is a traditional and culturally significant Pacific Island beverage that produces a soporific relaxant effect. Kava’s psychopharmacological action is similar to the anti-anxiety drug Benzodiazepine. Traditional users often consume the kava drink at volumes as much as 30 times greater than pharmacologically recommended doses. Prompted by concerns regarding driver impairment post kava drinking, a study was undertaken replicating traditional kava sessions in terms of duration and kava consumption, to investigate the effects of kava on driving capability.
Kava consumers (n=20) attended two six-hour kava sessions, each participant drinking an average 3.52 litres of kava. A non-kava consuming control group (n=20) was included in the study. At baseline all the participants completed computerised industry standard driver safety assessment tests (Vienna Test System: Traffic WAFA Alertness and WAFG Divided Attention) to measure reaction time, perception and attention. Re-testing was conducted at hourly intervals over the six-hour period. Pre/post analysis compared person to person and between groups change. Statistical modeling was based on ANOVA, independent t-tests and Bayesian analysis.
Data analysis indicated no statistically significant (p<0.05) difference between reaction time and divided attention, both within individuals and between groups, at any measurement point over the six-hour testing period. The mean reaction time and divided attention time at the baseline measurement was 249.95msec (milliseconds) and 583.58msec respectively. The control and active group mean reaction time at the final test was 256.70msec and 271.8msec respectively. The mean divided attention times for the control and active groups at the final test were 499.75msec and 568.32msec.
Kava at traditional consumption volumes was not correlated to response latency or impairment on perception and attention tasks, when measured using authoritative driver assessment tests. From this it could be inferred that kava use at traditionally influenced consumption volumes does not compromise driver safety. However, it can be argued that current industry standard accepted cognitive measures of driver safety, assess impairment from the use of euphoric and hallucinogenic drug substances (such as alcohol and marijuana), and fail to account for kava’s unique form of ‘intoxication’. Further research beyond the assessment of these two cognitive functions is, it seems, desirable to better understand if kava has any effect on driver ability.
The study was funded by the Health Research Council of New Zealand (16/462) and the University of Waikato, and the test battery was generously donated by Vienna Tests Systems, Germany.

text: Improving road safety and health: Understandng kava's impact on driver fitness. Kava (Piper methysticum) is a traditional and culturally significant Pacific Island beverage that produces a soporific relaxant effect. Kava’s psychopharmacological action is similar to the anti-anxiety drug Benzodiazepine. Traditional users often consume the kava drink at volumes as much as 30 times greater than pharmacologically recommended doses. Prompted by concerns regarding driver impairment post kava drinking, a study was undertaken replicating traditional kava sessions in terms of duration and kava consumption, to investigate the effects of kava on driving capability.
Kava consumers (n=20) attended two six-hour kava sessions, each participant drinking an average 3.52 litres of kava. A non-kava consuming control group (n=20) was included in the study. At baseline all the participants completed computerised industry standard driver safety assessment tests (Vienna Test System: Traffic WAFA Alertness and WAFG Divided Attention) to measure reaction time, perception and attention. Re-testing was conducted at hourly intervals over the six-hour period. Pre/post analysis compared person to person and between groups change. Statistical modeling was based on ANOVA, independent t-tests and Bayesian analysis.
Data analysis indicated no statistically significant (p<0.05) difference between reaction time and divided attention, both within individuals and between groups, at any measurement point over the six-hour testing period. The mean reaction time and divided attention time at the baseline measurement was 249.95msec (milliseconds) and 583.58msec respectively. The control and active group mean reaction time at the final test was 256.70msec and 271.8msec respectively. The mean divided attention times for the control and active groups at the final test were 499.75msec and 568.32msec.
Kava at traditional consumption volumes was not correlated to response latency or impairment on perception and attention tasks, when measured using authoritative driver assessment tests. From this it could be inferred that kava use at traditionally influenced consumption volumes does not compromise driver safety. However, it can be argued that current industry standard accepted cognitive measures of driver safety, assess impairment from the use of euphoric and hallucinogenic drug substances (such as alcohol and marijuana), and fail to account for kava’s unique form of ‘intoxication’. Further research beyond the assessment of these two cognitive functions is, it seems, desirable to better understand if kava has any effect on driver ability.
The study was funded by the Health Research Council of New Zealand (16/462) and the University of Waikato, and the test battery was generously donated by Vienna Tests Systems, Germany.

year: 2018

title: Long term nitrate removal in a denitrification wall

authors: Long, Lauren M.

subjects: bioreactor

abstract: Nitrogen (N) inputs to groundwater are one of the most widespread environmental problems globally. However, as N is important for crop production to support the current global population, it is difficult to limit N input to an extent where groundwater contamination is completely avoided. Researchers have been testing new ways to remove N (in the form of nitrate (NO3-)) from groundwater, primarily through enhancing microbial denitrification. One technology utilizing this microbial process is a denitrification wall, which is an inexpensive, low-maintenance technology compared to other options to treat NO3--contaminated groundwater. Denitrification walls have been shown to be effective for removing NO3- from groundwater through denitrification for seven years in New Zealand, nine years in Iowa, and 15 years in Canada; however, long-term data on the efficacy of denitrification walls remain limited. In order to understand how these systems function in the long term, the performance of a New Zealand denitrification wall installed in 1996 was examined. Field sampling was carried out during the winter of 2010 at the denitrification wall at Bardowie Farm in Cambridge, New Zealand. This farm had received relatively high N inputs from spray-irrigation of effluent from the nearby Hautapu Dairy Factory for over 30 years. The denitrification wall was originally constructed by mixing 40 m3 Pinus radiata sawdust with soil down to a depth of 1.5 m where it intercepted groundwater flow. Groundwater samples were collected from wells installed upslope and within the wall and samples were analyzed for NO3- concentrations on five occasions. Soil samples were collected on four occasions from below the water table and analyzed for denitrifying enzyme activity (DEA), total carbon (C), available C, and microbial biomass C. Results were compared to previous measurements. Groundwater NO3- concentrations entering the wall averaged 2.6 mg N L-1, which was a decrease from 2002 where NO3- entered the wall at an average of 9 mg N L-1. Despite this decrease, NO3- concentrations within the wall averaged 0.2 mg N L-1, which corresponded to 92% NO3- removal. DEA rates in the wall were nearly as high as the first year of construction. In contrast, total C and microbial biomass C had decreased by half, while available C remained the same as measured two years after construction. Denitrification in the wall remained NO3- limited suggesting that C was still sufficiently available to the denitrifiers. These data indicated that the denitrification wall was still effective after 14 years. To predict denitrification wall longevity, a first-order decay curve was fitted to the total C data through time (R2 = 0.92; p < 0.05). The decay curve was used to predict the time until total C reached 0.1%, although it is unclear at what %C denitrification will become C limited. Using this decay curve, it was estimated that C in the wall would not be depleted for 66 years, although it is possible that C will become limiting to denitrifiers before that time. This long-term study suggested that denitrification walls are cost-effective solutions to removing NO3- from groundwater as they can be effective for a number of years without any maintenance.

text: Long term nitrate removal in a denitrification wall Nitrogen (N) inputs to groundwater are one of the most widespread environmental problems globally. However, as N is important for crop production to support the current global population, it is difficult to limit N input to an extent where groundwater contamination is completely avoided. Researchers have been testing new ways to remove N (in the form of nitrate (NO3-)) from groundwater, primarily through enhancing microbial denitrification. One technology utilizing this microbial process is a denitrification wall, which is an inexpensive, low-maintenance technology compared to other options to treat NO3--contaminated groundwater. Denitrification walls have been shown to be effective for removing NO3- from groundwater through denitrification for seven years in New Zealand, nine years in Iowa, and 15 years in Canada; however, long-term data on the efficacy of denitrification walls remain limited. In order to understand how these systems function in the long term, the performance of a New Zealand denitrification wall installed in 1996 was examined. Field sampling was carried out during the winter of 2010 at the denitrification wall at Bardowie Farm in Cambridge, New Zealand. This farm had received relatively high N inputs from spray-irrigation of effluent from the nearby Hautapu Dairy Factory for over 30 years. The denitrification wall was originally constructed by mixing 40 m3 Pinus radiata sawdust with soil down to a depth of 1.5 m where it intercepted groundwater flow. Groundwater samples were collected from wells installed upslope and within the wall and samples were analyzed for NO3- concentrations on five occasions. Soil samples were collected on four occasions from below the water table and analyzed for denitrifying enzyme activity (DEA), total carbon (C), available C, and microbial biomass C. Results were compared to previous measurements. Groundwater NO3- concentrations entering the wall averaged 2.6 mg N L-1, which was a decrease from 2002 where NO3- entered the wall at an average of 9 mg N L-1. Despite this decrease, NO3- concentrations within the wall averaged 0.2 mg N L-1, which corresponded to 92% NO3- removal. DEA rates in the wall were nearly as high as the first year of construction. In contrast, total C and microbial biomass C had decreased by half, while available C remained the same as measured two years after construction. Denitrification in the wall remained NO3- limited suggesting that C was still sufficiently available to the denitrifiers. These data indicated that the denitrification wall was still effective after 14 years. To predict denitrification wall longevity, a first-order decay curve was fitted to the total C data through time (R2 = 0.92; p < 0.05). The decay curve was used to predict the time until total C reached 0.1%, although it is unclear at what %C denitrification will become C limited. Using this decay curve, it was estimated that C in the wall would not be depleted for 66 years, although it is possible that C will become limiting to denitrifiers before that time. This long-term study suggested that denitrification walls are cost-effective solutions to removing NO3- from groundwater as they can be effective for a number of years without any maintenance.

year: 2011

title: Maori thinking with a dead white male: Philosophizing in the realm of Novalis

authors: Mika, Carl Te Hira

subjects: Novalis

abstract: In this paper I shall discuss my experiences of referring to Novalis in the context of Maori postcolonialism and metaphysical philosophy. As with other methods of research, from a Maori perspective one always alights on and then carries the effects of the philosopher that stands behind the method, whether the philosopher is silent or explicit. This important onto-epistemological interaction, in a general sense, acknowledges for the indigenous person that one is always ‘within’ the world and not detached from it. The maligned dead white male hence unavoidably becomes the highly constructive, living impulse behind what is to become fresh and innovative indigenous thinking.

text: Maori thinking with a dead white male: Philosophizing in the realm of Novalis In this paper I shall discuss my experiences of referring to Novalis in the context of Maori postcolonialism and metaphysical philosophy. As with other methods of research, from a Maori perspective one always alights on and then carries the effects of the philosopher that stands behind the method, whether the philosopher is silent or explicit. This important onto-epistemological interaction, in a general sense, acknowledges for the indigenous person that one is always ‘within’ the world and not detached from it. The maligned dead white male hence unavoidably becomes the highly constructive, living impulse behind what is to become fresh and innovative indigenous thinking.

year: 2014