title: The synthesis and  reactivity of B-aryl {i.e. Beta -aryl} lignin model quinone methides

authors: Ede, Richard Michael

subjects: Wood-pulping chemistry

abstract: ﻿A range of l,2-diarylpropane-1,3-diols and 2,3-dihydro-2-aryl-7- methoxy-benzofurans were synthesised as model compounds for the B-5 (phenylcoumaran) structural unit found in wood lignin. The syntheses were performed following either established, or modifications of established procedures. Preliminary studies were carried out which showed the viability of a new general synthesis for B-aryl lignin model compounds. 
Phenylboronates of three of the l,2-diarylpropane-1,3-diols were synthesised. The ¹H NMR coupling constants observed between the vicinal protons on the 6-membered ring confirmed the previously inferred erythro stereochemistry. Single crystal X-ray diffraction structures were obtained of 2,3-dihydro-2-(4-hydroxy-3- methoxyphenyl)-3-methyl-5-propyl-7-methoxybenzofuran and l-(4-hydroxy-3-methoxyphenyl-2-(2,3-dimethoxyphenyl)-propane-l,3- diacetate. 
Quinone methides (4-methylene-cyclohexa-2,5-dienones) derived from the B-5 lignin model compounds were treated with anthranol (a reduced form of anthraquinone, AQ, found in soda-anthraquinone pulping liquors) to form a range of adducts. Anthrahydroquinone, the major catalytic species in the soda-AQ process, would not add to the quinone methides. The presence of erythro and threo isomers of the anthranol adducts was observed by ¹H and ¹³C NMR, and in some cases a preparative chromatographic separation of the two isomers was possible. The addition of anthranol to the quinone methides was shown to be reversible. The erythro adduct was found to be kinetically preferred, but over long reaction times, the threo isomer predominated. It was shown that for quinone methides possessing the B-hydroxymethyl group, the retro-aldol elimination of formaldehyde to give stilbenes took precedence over adduct formation. Thus, stilbene formation was believed to be that which occurs for phenylcoumaran and B-C-1 structures when reacted under soda-AQ pulping conditions, and the reactions of these structures would not contribute to delignification. Conversely, it was not expected that the phenylcoumaran and B-C-1 structures would contribute to the loss of AQ from the process. 
The stabilised quinone methides were characterised by ¹H and ¹³C NMR. It was found that these and previously synthesised quinone methides derived from the B-aryl ether lignin structure, existed in solution as a mixture of two isomers in a ratio of 2:1, SYN:ANTI. The preference for the formation of the SYN isomer was believed to be either product-controlled or from conformational equilibrium control in the transition-state leading to the quinone methide. It was found by a ¹H NMR method that the ANTI isomers of all the quinone methides studied reacted with amines approximately 40% faster than the SYN isomers. It was not possible to determine if this difference in reactivity would be exhibited by quinone methides reacted under pulping conditions.

text: The synthesis and  reactivity of B-aryl {i.e. Beta -aryl} lignin model quinone methides ﻿A range of l,2-diarylpropane-1,3-diols and 2,3-dihydro-2-aryl-7- methoxy-benzofurans were synthesised as model compounds for the B-5 (phenylcoumaran) structural unit found in wood lignin. The syntheses were performed following either established, or modifications of established procedures. Preliminary studies were carried out which showed the viability of a new general synthesis for B-aryl lignin model compounds. 
Phenylboronates of three of the l,2-diarylpropane-1,3-diols were synthesised. The ¹H NMR coupling constants observed between the vicinal protons on the 6-membered ring confirmed the previously inferred erythro stereochemistry. Single crystal X-ray diffraction structures were obtained of 2,3-dihydro-2-(4-hydroxy-3- methoxyphenyl)-3-methyl-5-propyl-7-methoxybenzofuran and l-(4-hydroxy-3-methoxyphenyl-2-(2,3-dimethoxyphenyl)-propane-l,3- diacetate. 
Quinone methides (4-methylene-cyclohexa-2,5-dienones) derived from the B-5 lignin model compounds were treated with anthranol (a reduced form of anthraquinone, AQ, found in soda-anthraquinone pulping liquors) to form a range of adducts. Anthrahydroquinone, the major catalytic species in the soda-AQ process, would not add to the quinone methides. The presence of erythro and threo isomers of the anthranol adducts was observed by ¹H and ¹³C NMR, and in some cases a preparative chromatographic separation of the two isomers was possible. The addition of anthranol to the quinone methides was shown to be reversible. The erythro adduct was found to be kinetically preferred, but over long reaction times, the threo isomer predominated. It was shown that for quinone methides possessing the B-hydroxymethyl group, the retro-aldol elimination of formaldehyde to give stilbenes took precedence over adduct formation. Thus, stilbene formation was believed to be that which occurs for phenylcoumaran and B-C-1 structures when reacted under soda-AQ pulping conditions, and the reactions of these structures would not contribute to delignification. Conversely, it was not expected that the phenylcoumaran and B-C-1 structures would contribute to the loss of AQ from the process. 
The stabilised quinone methides were characterised by ¹H and ¹³C NMR. It was found that these and previously synthesised quinone methides derived from the B-aryl ether lignin structure, existed in solution as a mixture of two isomers in a ratio of 2:1, SYN:ANTI. The preference for the formation of the SYN isomer was believed to be either product-controlled or from conformational equilibrium control in the transition-state leading to the quinone methide. It was found by a ¹H NMR method that the ANTI isomers of all the quinone methides studied reacted with amines approximately 40% faster than the SYN isomers. It was not possible to determine if this difference in reactivity would be exhibited by quinone methides reacted under pulping conditions.

year: 1987

title: The language environment of primary school aged children in Tonga: A case study of 4 children

authors: Puniani, Talaifina Monalisa

subjects: language input

abstract: The Ministry of Education and Training in Tonga’s direction for its language policy has recently changed and at present, all the local schools are expected to implement effectively the new language policy that was in place in the early 2000’s. Under the UNESCO and the World Bank’s influence, the new language policy articulates the teaching of children from an early age in their local vernacular to establish literacy in the first language before the introduction of English at Class 3 of the primary school level. 
This study was conducted in light of this new policy, to explore from a primary school in Tonga the language environments that children experience to identify whether or not the language input they receive is sufficient for balanced bilingualism to be supported. The study also was a way to explore children’s understanding of their language environment and choices. It was a way to help out parents and teachers understand the kind of language environment that fosters balanced bilinguals.
The scope of this study, being a Master’s thesis, allowed me to use a case study for this research. Four participants from a primary school in Tonga was used for collection of the data. The research took on a qualitative approach with data being generated using two main methods: field observations (both in the classroom and at home) and a focus group interview. The data generated from these methods captured what was observed in the participant’s natural environment setting (i.e. the classroom and at home) which included what language is used, who said it and to whom, the activities that were done during the use of language (i.e. what the participants did). The data also provided the childrens’ own views of their language choices without the influence of adults to think for them.
It was apparent from the research that although the language policy in place was affirmative of students being bilinguals, there was a huge gap that student participants were experiencing with their language input especially with the use of English and with being given the opportunities to use language to ensure that they have learnt and mastered the input they have received. Both the observations and the focus group identified the dominance of the teacher in the classroom and the very few chances of input for students especially on their L2 and especially the opportunity to practice and use both the Tongan and the English language. 
The research therefore has indicated the fact that while teachers are indeed following part of the prescription of the language policy in Tonga in terms of exposing and establishing a firm foundation on the children at an early age to Tongan, they are not following it with respect to providing English input. The research hence suggests some implications not just for teachers but for the education system to address because there is a crucial need for all parties involved (administration, teachers, parents and students) to work collaboratively to identify and to address and improve the quantity and the quality of language input students receive.

text: The language environment of primary school aged children in Tonga: A case study of 4 children The Ministry of Education and Training in Tonga’s direction for its language policy has recently changed and at present, all the local schools are expected to implement effectively the new language policy that was in place in the early 2000’s. Under the UNESCO and the World Bank’s influence, the new language policy articulates the teaching of children from an early age in their local vernacular to establish literacy in the first language before the introduction of English at Class 3 of the primary school level. 
This study was conducted in light of this new policy, to explore from a primary school in Tonga the language environments that children experience to identify whether or not the language input they receive is sufficient for balanced bilingualism to be supported. The study also was a way to explore children’s understanding of their language environment and choices. It was a way to help out parents and teachers understand the kind of language environment that fosters balanced bilinguals.
The scope of this study, being a Master’s thesis, allowed me to use a case study for this research. Four participants from a primary school in Tonga was used for collection of the data. The research took on a qualitative approach with data being generated using two main methods: field observations (both in the classroom and at home) and a focus group interview. The data generated from these methods captured what was observed in the participant’s natural environment setting (i.e. the classroom and at home) which included what language is used, who said it and to whom, the activities that were done during the use of language (i.e. what the participants did). The data also provided the childrens’ own views of their language choices without the influence of adults to think for them.
It was apparent from the research that although the language policy in place was affirmative of students being bilinguals, there was a huge gap that student participants were experiencing with their language input especially with the use of English and with being given the opportunities to use language to ensure that they have learnt and mastered the input they have received. Both the observations and the focus group identified the dominance of the teacher in the classroom and the very few chances of input for students especially on their L2 and especially the opportunity to practice and use both the Tongan and the English language. 
The research therefore has indicated the fact that while teachers are indeed following part of the prescription of the language policy in Tonga in terms of exposing and establishing a firm foundation on the children at an early age to Tongan, they are not following it with respect to providing English input. The research hence suggests some implications not just for teachers but for the education system to address because there is a crucial need for all parties involved (administration, teachers, parents and students) to work collaboratively to identify and to address and improve the quantity and the quality of language input students receive.

year: 2017

title: Collectivism, cultural identity and employee mental health: A study of New Zealand Māori

authors: Brougham, David M.

subjects: Anxiety

abstract: Māori are a collectivistic people living within a largely individualistic country. The present study tested whether Māori who practice higher levels of workplace collectivism feel greater alignment with their overall cultural beliefs, and report better mental health results because of their lower levels of anxiety and depression. Three hundred and thirty-six Māori employees were surveyed, and a regression analysis showed significant direct effects, with collectivism accounting for a sizable 20 % of the variance in both anxiety and depression. Two moderators relating to cultural knowledge and cultural language were also tested. Significant two-way interactions were found: high collectivism and high cultural knowledge led to low depression, and high cultural knowledge and high cultural language skills led to low depression and anxiety. A three-way interaction was found between anxiety, collectivism and cultural knowledge and/or language: low anxiety was reported by respondents with high collectivism and either high cultural knowledge or cultural language. Overall, the study highlights the importance of collectivism and cultural identity for Māori employees' mental health

text: Collectivism, cultural identity and employee mental health: A study of New Zealand Māori Māori are a collectivistic people living within a largely individualistic country. The present study tested whether Māori who practice higher levels of workplace collectivism feel greater alignment with their overall cultural beliefs, and report better mental health results because of their lower levels of anxiety and depression. Three hundred and thirty-six Māori employees were surveyed, and a regression analysis showed significant direct effects, with collectivism accounting for a sizable 20 % of the variance in both anxiety and depression. Two moderators relating to cultural knowledge and cultural language were also tested. Significant two-way interactions were found: high collectivism and high cultural knowledge led to low depression, and high cultural knowledge and high cultural language skills led to low depression and anxiety. A three-way interaction was found between anxiety, collectivism and cultural knowledge and/or language: low anxiety was reported by respondents with high collectivism and either high cultural knowledge or cultural language. Overall, the study highlights the importance of collectivism and cultural identity for Māori employees' mental health

year: 2012