title: Analysis of the flavonoid component of bioactive New Zealand mānuka (Leptospermum scoparium) honey and the isolation, characterisation and synthesis of an unusual pyrrole

authors: Chan, Ching Wan

subjects: Mānuka honey

abstract: The flavonoid components of New Zealand mānuka (Leptospermum scoparium) honey have been quantified in a series of 31 honeys of varying non-peroxide antibacterial activity to clarify discrepancies between previous studies reported in the literature. Total flavonoid content was 1.16 mg/100 g honey. The principal flavonoids present were pinobanksin, pinocembrin, luteolin and chrysin and together these represented 61% of the total flavonoid content. 1, 2-formyl-5-(2-methoxyphenyl)-pyrrole, which was weakly correlated with the non-peroxide antibacterial activity, was isolated from the flavonoid fraction and separately synthesised. 1 did not display inhibitory activity against Staphylococcus aureus in vitro and thus the origin of the correlation, which is still unknown, is not a direct contribution.

text: Analysis of the flavonoid component of bioactive New Zealand mānuka (Leptospermum scoparium) honey and the isolation, characterisation and synthesis of an unusual pyrrole The flavonoid components of New Zealand mānuka (Leptospermum scoparium) honey have been quantified in a series of 31 honeys of varying non-peroxide antibacterial activity to clarify discrepancies between previous studies reported in the literature. Total flavonoid content was 1.16 mg/100 g honey. The principal flavonoids present were pinobanksin, pinocembrin, luteolin and chrysin and together these represented 61% of the total flavonoid content. 1, 2-formyl-5-(2-methoxyphenyl)-pyrrole, which was weakly correlated with the non-peroxide antibacterial activity, was isolated from the flavonoid fraction and separately synthesised. 1 did not display inhibitory activity against Staphylococcus aureus in vitro and thus the origin of the correlation, which is still unknown, is not a direct contribution.

year: 2013

title: DNA repair during bacterial competence? A potential role for the periplasmic ligase, Lig E

authors: Pan, Jolyn Tyn Tyn

abstract: The rapid rise in antibiotic resistance among pathogenic bacteria calls for better understanding of drivers of resistance and pathways by which it occurs. Identification of such mechanisms could identify novel pathways that can be targeted for therapeutic interventions. In particular, disruption of the DNA repair system, which includes ligases that seal breaks in DNA, would greatly discourage bacterial growth. Recently, an enigmatic ATP-dependent DNA ligase, Lig E, has been discovered in many species of antibiotic-resistant Gram-negative bacteria. This enzyme is not only minimal and compact, but also contains an N (amino)-terminal signal peptide that indicates a likely periplasmic location, as opposed to the cytoplasm, the location of genomic DNA. It is thus hypothesised that Lig E has a potential role in bacterial competence and aids in repairing breaks in damaged DNA obtained from the environment, a role which may enhance the acquisition of antibiotic resistance genes under DNA damaging conditions.
In recent years, there has been growing public concern about the human pathogen Neisseria gonorrhoeae, which causes the sexually transmitted disease, gonorrhoea. Previously easily treatable, this disease is now spreading at alarming rates due to the bacterium’s rapid acquisition of antibiotic resistance genes, attributable to its ability to take up pieces of DNA without regulation. It is in relation to this natural competence that Lig E is hypothesised to function, not only by accelerating the uptake process, but also by increasing the uptake efficiency. Thus, the aim of this thesis was to identify the cellular location and biological function of Lig E in N. gonorrhoeae (Ngo-Lig) by generating in vivo mutants, the effects of which were characterised both in vivo (growth experiment) and in vitro (ligation assays). Steps were also made towards developing an in vivo assay to test the role of Ngo-Lig in DNA uptake by optimisation of uptake reporter constructs.
Results obtained over the course of this thesis showed that disruption of Lig E in N. gonorrhoeae leads to a decrease in the rates of gonococcal growth. From this, the hypothesis of the role of Lig E evolved to also consider its potential role in biofilm formation, which is important for the bacterium’s attachment and infection.
Although further research into the biological role of Lig E are necessary, the results collected demonstrated potentially novel pathways involving Lig E that may be targeted by future drug developments to tackle this emerging threat in our community.

text: DNA repair during bacterial competence? A potential role for the periplasmic ligase, Lig E The rapid rise in antibiotic resistance among pathogenic bacteria calls for better understanding of drivers of resistance and pathways by which it occurs. Identification of such mechanisms could identify novel pathways that can be targeted for therapeutic interventions. In particular, disruption of the DNA repair system, which includes ligases that seal breaks in DNA, would greatly discourage bacterial growth. Recently, an enigmatic ATP-dependent DNA ligase, Lig E, has been discovered in many species of antibiotic-resistant Gram-negative bacteria. This enzyme is not only minimal and compact, but also contains an N (amino)-terminal signal peptide that indicates a likely periplasmic location, as opposed to the cytoplasm, the location of genomic DNA. It is thus hypothesised that Lig E has a potential role in bacterial competence and aids in repairing breaks in damaged DNA obtained from the environment, a role which may enhance the acquisition of antibiotic resistance genes under DNA damaging conditions.
In recent years, there has been growing public concern about the human pathogen Neisseria gonorrhoeae, which causes the sexually transmitted disease, gonorrhoea. Previously easily treatable, this disease is now spreading at alarming rates due to the bacterium’s rapid acquisition of antibiotic resistance genes, attributable to its ability to take up pieces of DNA without regulation. It is in relation to this natural competence that Lig E is hypothesised to function, not only by accelerating the uptake process, but also by increasing the uptake efficiency. Thus, the aim of this thesis was to identify the cellular location and biological function of Lig E in N. gonorrhoeae (Ngo-Lig) by generating in vivo mutants, the effects of which were characterised both in vivo (growth experiment) and in vitro (ligation assays). Steps were also made towards developing an in vivo assay to test the role of Ngo-Lig in DNA uptake by optimisation of uptake reporter constructs.
Results obtained over the course of this thesis showed that disruption of Lig E in N. gonorrhoeae leads to a decrease in the rates of gonococcal growth. From this, the hypothesis of the role of Lig E evolved to also consider its potential role in biofilm formation, which is important for the bacterium’s attachment and infection.
Although further research into the biological role of Lig E are necessary, the results collected demonstrated potentially novel pathways involving Lig E that may be targeted by future drug developments to tackle this emerging threat in our community.

year: 2021

title: Conscientisation and Resistance: Experiences from implementing a culturally responsive pedagogy of relations

authors: Lawrence, Dawn Cherie

subjects: culturally responsive pedagogy of relations

abstract: Consciousness of being part of a particular hegemonic force (that is to say,political consciousness) is the first stage towards a further progressive self –conscious in which theory and practice will finally be one. (Hoare & Smith,1971, p. 333)

Bishop, Berryman, Tiakiwai and Richardson, (2003) state that effective teachers of Māori students “positively and vehemently reject deficit theorizing as a means of explaining Māori students’ educational achievement” (p.95). This fundamental tenet of the Te Kotahitanga Effective Teaching Profile (ETP) moves beyond simply refraining from publicly articulating discourses that pathologise Māori students and their whānau (Bishop et al., 2003; Bishop & Berryman, 2006; Bishop, Berryman, Cavanagh, & Teddy. 2007). For many teachers it is a challenging, ongoing transformative process of critical self-reflection, which touches the very core of their own culture and identity.

This thesis contends that by working to discursively position themselves within a culturally responsive pedagogy of relations, teachers develop classroom practices that have been shown to positively affect outcomes for Māori students. It goes on to suggest that such discursive repositioning might be seen as praxis, with the potential to transform the inequities experienced by Māori within mainstream educational settings. With this understanding, the culture and leadership approach of the school context becomes a greater influence on teachers’ capacity to realize their agency within this pedagogy than any characteristic of the individual.

text: Conscientisation and Resistance: Experiences from implementing a culturally responsive pedagogy of relations Consciousness of being part of a particular hegemonic force (that is to say,political consciousness) is the first stage towards a further progressive self –conscious in which theory and practice will finally be one. (Hoare & Smith,1971, p. 333)

Bishop, Berryman, Tiakiwai and Richardson, (2003) state that effective teachers of Māori students “positively and vehemently reject deficit theorizing as a means of explaining Māori students’ educational achievement” (p.95). This fundamental tenet of the Te Kotahitanga Effective Teaching Profile (ETP) moves beyond simply refraining from publicly articulating discourses that pathologise Māori students and their whānau (Bishop et al., 2003; Bishop & Berryman, 2006; Bishop, Berryman, Cavanagh, & Teddy. 2007). For many teachers it is a challenging, ongoing transformative process of critical self-reflection, which touches the very core of their own culture and identity.

This thesis contends that by working to discursively position themselves within a culturally responsive pedagogy of relations, teachers develop classroom practices that have been shown to positively affect outcomes for Māori students. It goes on to suggest that such discursive repositioning might be seen as praxis, with the potential to transform the inequities experienced by Māori within mainstream educational settings. With this understanding, the culture and leadership approach of the school context becomes a greater influence on teachers’ capacity to realize their agency within this pedagogy than any characteristic of the individual.

year: 2014