title: The effect of cyanobacterial biomass enrichment by centrifugation and GF/C filtration on subsequent microcystin measurement

authors: Rogers, Shelley

abstract: Microcystins are cyclic peptides produced by multiple cyanobacterial genera. After accumulation in the liver of animals they inhibit eukaryotic serine/threonine protein phosphatases, causing liver disease or death. Accurate detection/quantification of microcystins is essential to ensure safe water resources and to enable research on this toxin. Previous methodological comparisons have focused on detection and extraction techniques, but have not investigated the commonly used biomass enrichment steps. These enrichment steps could modulate toxin production as recent studies have demonstrated that high cyanobacterial cell densities cause increased microcystin levels. In this study, three microcystin-producing strains were processed using no cell enrichment steps (by direct freezing at three temperatures) and with biomass enrichment (by centrifugation or GF/C filtration). After extraction, microcystins were analyzed using liquid chromatography-tandem mass spectrometry. All processing methods tested, except GF/C filtration, resulted in comparable microcystin quotas for all strains. The low yields observed for the filtration samples were caused by adsorption of arginine-containing microcystins to the GF/C filters. Whilst biomass enrichment did not affect microcystin metabolism over the time-frame of normal sample processing, problems associated with GF/C filtration were identified. The most widely applicable processing method was direct freezing of samples as it could be utilized in both field and laboratory environments.

text: The effect of cyanobacterial biomass enrichment by centrifugation and GF/C filtration on subsequent microcystin measurement Microcystins are cyclic peptides produced by multiple cyanobacterial genera. After accumulation in the liver of animals they inhibit eukaryotic serine/threonine protein phosphatases, causing liver disease or death. Accurate detection/quantification of microcystins is essential to ensure safe water resources and to enable research on this toxin. Previous methodological comparisons have focused on detection and extraction techniques, but have not investigated the commonly used biomass enrichment steps. These enrichment steps could modulate toxin production as recent studies have demonstrated that high cyanobacterial cell densities cause increased microcystin levels. In this study, three microcystin-producing strains were processed using no cell enrichment steps (by direct freezing at three temperatures) and with biomass enrichment (by centrifugation or GF/C filtration). After extraction, microcystins were analyzed using liquid chromatography-tandem mass spectrometry. All processing methods tested, except GF/C filtration, resulted in comparable microcystin quotas for all strains. The low yields observed for the filtration samples were caused by adsorption of arginine-containing microcystins to the GF/C filters. Whilst biomass enrichment did not affect microcystin metabolism over the time-frame of normal sample processing, problems associated with GF/C filtration were identified. The most widely applicable processing method was direct freezing of samples as it could be utilized in both field and laboratory environments.

year: 2015-03

title: Controlled intoxication: the self-monitoring of excessive alcohol use within a New Zealand tertiary student sample

authors: McEwan, Brett James

subjects: drinking

abstract: Aims: Drawn from a study aimed at exploring students’ drinking behaviour and attitudes, this article focuses upon findings that revealed how heavy-drinking students monitored and managed their experiences of alcohol intoxication.
Methods: 819 students residing within three university student residences were invited to participate in three phases of data collection. Utilising a combination of qualitative and quantitative research methods, a total of 15 focus group interviews and 18 indepth interviews were undertaken, and 501 students (61%) completed a written survey questionnaire. 
Results: Sixty percent of students agreed with the statement “I usually know beforehand if I am going to get drunk”. One-half of male drinkers and one-third of female drinkers reported they were intoxicated on a weekly basis. When drinking to intoxication, the majority of students monitored a range of drinking effects (a total of 14 were identified) which they considered were signals for the need to either slow down or stop drinking. 
Conclusions: The majority of drinkers in this study who consume alcohol with the intention of getting intoxicated, typically drink to a predetermined level of intoxication, and maintain that level by monitoring a range of drinking effects—this behaviour has been termed controlled intoxication. Future harm-minimisation strategies could be developed that encourage heavy-drinkers to adopt ‘safer’ drinking-effect signals as indicators to slow down or stop drinking.

text: Controlled intoxication: the self-monitoring of excessive alcohol use within a New Zealand tertiary student sample Aims: Drawn from a study aimed at exploring students’ drinking behaviour and attitudes, this article focuses upon findings that revealed how heavy-drinking students monitored and managed their experiences of alcohol intoxication.
Methods: 819 students residing within three university student residences were invited to participate in three phases of data collection. Utilising a combination of qualitative and quantitative research methods, a total of 15 focus group interviews and 18 indepth interviews were undertaken, and 501 students (61%) completed a written survey questionnaire. 
Results: Sixty percent of students agreed with the statement “I usually know beforehand if I am going to get drunk”. One-half of male drinkers and one-third of female drinkers reported they were intoxicated on a weekly basis. When drinking to intoxication, the majority of students monitored a range of drinking effects (a total of 14 were identified) which they considered were signals for the need to either slow down or stop drinking. 
Conclusions: The majority of drinkers in this study who consume alcohol with the intention of getting intoxicated, typically drink to a predetermined level of intoxication, and maintain that level by monitoring a range of drinking effects—this behaviour has been termed controlled intoxication. Future harm-minimisation strategies could be developed that encourage heavy-drinkers to adopt ‘safer’ drinking-effect signals as indicators to slow down or stop drinking.

year: 2011

title: Maori syllabus and the curriculum documents: A critical analysis. Part 1: Tihe Mauri Ora

authors: Crombie, Winifred

subjects: Te reo Māori

abstract: This paper presents, within the context of ongoing debates on syllabus design, a critical analysis of Tihē Mauri Ora, a syllabus document produced by the New Zealand Ministry of Education to support the teaching and learning of the Māori language in schools in New Zealand. It includes a number of suggestions in relation to any future documents prepared with similar intent.

text: Maori syllabus and the curriculum documents: A critical analysis. Part 1: Tihe Mauri Ora This paper presents, within the context of ongoing debates on syllabus design, a critical analysis of Tihē Mauri Ora, a syllabus document produced by the New Zealand Ministry of Education to support the teaching and learning of the Māori language in schools in New Zealand. It includes a number of suggestions in relation to any future documents prepared with similar intent.

year: 2001