title: Novel New Zealand marine bioactive natural products for the control of Psa biovar 3

authors: Browne, Ashleigh Joan

abstract: Natural products (secondary metabolites), produced by living organisms to confer selective advantages via chemical-ecological interactions, have had extensive use in biodiscovery programmes and commercial applications. Such compounds are a unique source of chemical and structural novelty and thus provide relevant modes of biological activity unsurpassed by synthetic compounds. The marine environment has become recognised as an important natural product resource in recent years. Increasing interest is attributed to its high biodiversity, which is complemented by an elaborate chemical diversity in marine organisms. Of particular interest are those sessile and colonial marine organisms which utilise secondary metabolites for chemical defence. 

Marine natural products represent unexplored potential for control of the causal agent of bacterial canker of kiwifruit, Pseudomonas syringae pv. actinidiae (Psa) biovar 3. Very few options are available to control the highly virulent pathogen, hence there is an urgent need to find alternative products which kill or inhibit Psa. Previous natural product discovery programmes informed the chance of discovering ‘hit’ activity is low. To increase the chance of success, this study focused on previous biomedicinal work examining related organisms with known activity against Pseudomonas aeruginosa and bacterial quorum sensing processes (known as ecologically guided discovery).  

The study sought to identify bioactive compounds from marine organisms with biological activity against P. syringae pv. actinidiae biovar 3. Nineteen New Zealand macroalgae specimens collected in summer and winter were screened for preliminary biological activity against Psa biovar 3. Five candidates (26 percent) were identified with ‘hit’ activity; of which 16 percent was attributed to those targeted for screening and 10 percent is attributed to those selected at random. The secondary screening phase identified the presence of four brominated ions in Vidalia colensoi, m/z 278.8, 308.8, 421.8, and 311.9, as likely to represent biologically active compounds of interest against Psa. There is currently no evidence to suggest these ions represent previously isolated compounds. Hence, Vidalia colensoi is the species of highest priority to further explore chemically. The elicitor screening phase informed that further considerations are to be made for an effective higher order screening method to examine the macroalgae for elicitor activity against Psa biovar 3. 

In summary, the findings of this study suggest than ecologically guided discovery approach effectively directed the selection of species with ‘hit’ activity against Psa biovar 3 and thus fast tracked the initial discovery phase. Secondly, the discovery of four previously unidentified brominated ions with potential biological activity against Psa suggests they may represent structurally novel compounds with commercial patentability and marketability. Lastly, the elicitor screening findings provided important preliminary information for optimisation of higher level screening process to explore elicitor activity as a mode of action against Psa biovar 3.

text: Novel New Zealand marine bioactive natural products for the control of Psa biovar 3 Natural products (secondary metabolites), produced by living organisms to confer selective advantages via chemical-ecological interactions, have had extensive use in biodiscovery programmes and commercial applications. Such compounds are a unique source of chemical and structural novelty and thus provide relevant modes of biological activity unsurpassed by synthetic compounds. The marine environment has become recognised as an important natural product resource in recent years. Increasing interest is attributed to its high biodiversity, which is complemented by an elaborate chemical diversity in marine organisms. Of particular interest are those sessile and colonial marine organisms which utilise secondary metabolites for chemical defence. 

Marine natural products represent unexplored potential for control of the causal agent of bacterial canker of kiwifruit, Pseudomonas syringae pv. actinidiae (Psa) biovar 3. Very few options are available to control the highly virulent pathogen, hence there is an urgent need to find alternative products which kill or inhibit Psa. Previous natural product discovery programmes informed the chance of discovering ‘hit’ activity is low. To increase the chance of success, this study focused on previous biomedicinal work examining related organisms with known activity against Pseudomonas aeruginosa and bacterial quorum sensing processes (known as ecologically guided discovery).  

The study sought to identify bioactive compounds from marine organisms with biological activity against P. syringae pv. actinidiae biovar 3. Nineteen New Zealand macroalgae specimens collected in summer and winter were screened for preliminary biological activity against Psa biovar 3. Five candidates (26 percent) were identified with ‘hit’ activity; of which 16 percent was attributed to those targeted for screening and 10 percent is attributed to those selected at random. The secondary screening phase identified the presence of four brominated ions in Vidalia colensoi, m/z 278.8, 308.8, 421.8, and 311.9, as likely to represent biologically active compounds of interest against Psa. There is currently no evidence to suggest these ions represent previously isolated compounds. Hence, Vidalia colensoi is the species of highest priority to further explore chemically. The elicitor screening phase informed that further considerations are to be made for an effective higher order screening method to examine the macroalgae for elicitor activity against Psa biovar 3. 

In summary, the findings of this study suggest than ecologically guided discovery approach effectively directed the selection of species with ‘hit’ activity against Psa biovar 3 and thus fast tracked the initial discovery phase. Secondly, the discovery of four previously unidentified brominated ions with potential biological activity against Psa suggests they may represent structurally novel compounds with commercial patentability and marketability. Lastly, the elicitor screening findings provided important preliminary information for optimisation of higher level screening process to explore elicitor activity as a mode of action against Psa biovar 3.

year: 2016

title: Sentence initial lexical bundles in Chinese and New Zealand PhD theses in the discipline of General and Applied Linguistics

authors: Li, Liang

abstract: Lexical bundles are recurrent multiword combinations and often function as discourse building blocks. Lexical bundles have been analysed in university students’ writing to detect linguistic errors, measure writing competence, and investigate the divergence between L1 and L2 writing. Few studies, however, have focused on the high-stakes genre of PhD thesis and investigated the bundle productions of the same genre within the same level and discipline. This paper compares sentence initial lexical bundles in the corpora of English theses written by Chinese and New Zealand PhD students in the discipline of General and Applied Linguistics. Forty-six bundles from a Chinese corpus and forty-two bundles from a New Zealand corpus were generated. Among them, 94% of sentence initial bundles were identified as metadiscursive bundles. Chinese and New Zealand doctoral students showed considerably different preferences in their bundle selection. The paper examines the possible impact of these preferences and suggests there is a need to extend the metadiscourse knowledge of doctoral students in terms of lexical bundles.

text: Sentence initial lexical bundles in Chinese and New Zealand PhD theses in the discipline of General and Applied Linguistics Lexical bundles are recurrent multiword combinations and often function as discourse building blocks. Lexical bundles have been analysed in university students’ writing to detect linguistic errors, measure writing competence, and investigate the divergence between L1 and L2 writing. Few studies, however, have focused on the high-stakes genre of PhD thesis and investigated the bundle productions of the same genre within the same level and discipline. This paper compares sentence initial lexical bundles in the corpora of English theses written by Chinese and New Zealand PhD students in the discipline of General and Applied Linguistics. Forty-six bundles from a Chinese corpus and forty-two bundles from a New Zealand corpus were generated. Among them, 94% of sentence initial bundles were identified as metadiscursive bundles. Chinese and New Zealand doctoral students showed considerably different preferences in their bundle selection. The paper examines the possible impact of these preferences and suggests there is a need to extend the metadiscourse knowledge of doctoral students in terms of lexical bundles.

year: 2022-09-21

title: Waikirikiri Marae: Shared experiences of the wharemate

authors: Rua, Hare

subjects: Māori

abstract: In Te Urewera, wharemate (shelters in which the deceased receive their final farewells) have traditionally been temporary structures. In the 1980s, a new practice was introduced in the Ruātoki valley with the erection of permanent wharemate facilities. One was erected at Waikirikiri marae (tribal meeting grounds and associated buildings) in 1989. Knowledge and discussion regarding wharemate at Waikirikiri marae have changed over the years, and a whole generation has not been fortunate enough to experience tikanga (correct procedures, customary practices) that prevailed prior to the introduction of the permanent wharemate building that is there today. These changes are recorded in this paper through the shared stories of three kaumātua (elders) from Waikirikiri.

This paper is a summary of Hare Rua’s thesis study, the data for which was collected in 2009. This work forms part of the Tangi Research Programme, a collaboration between the School of Māori and Pacific Development and the Māori and Psychology Research Unit at The University of Waikato, Hamilton, New Zealand.

text: Waikirikiri Marae: Shared experiences of the wharemate In Te Urewera, wharemate (shelters in which the deceased receive their final farewells) have traditionally been temporary structures. In the 1980s, a new practice was introduced in the Ruātoki valley with the erection of permanent wharemate facilities. One was erected at Waikirikiri marae (tribal meeting grounds and associated buildings) in 1989. Knowledge and discussion regarding wharemate at Waikirikiri marae have changed over the years, and a whole generation has not been fortunate enough to experience tikanga (correct procedures, customary practices) that prevailed prior to the introduction of the permanent wharemate building that is there today. These changes are recorded in this paper through the shared stories of three kaumātua (elders) from Waikirikiri.

This paper is a summary of Hare Rua’s thesis study, the data for which was collected in 2009. This work forms part of the Tangi Research Programme, a collaboration between the School of Māori and Pacific Development and the Māori and Psychology Research Unit at The University of Waikato, Hamilton, New Zealand.

year: 2010