title: A genus in the bacterial phylum Aquificota appears to be endemic to Aotearoa-New Zealand.

authors: Power, Jean F.

subjects: New Zealand

abstract: Allopatric speciation has been difficult to examine among microorganisms, with prior reports of endemism restricted to sub-genus level taxa. Previous microbial community analysis via 16S rRNA gene sequencing of 925 geothermal springs from the Taupō Volcanic Zone (TVZ), Aotearoa-New Zealand, revealed widespread distribution and abundance of a single bacterial genus across 686 of these ecosystems (pH 1.2-9.6 and 17.4-99.8 °C). Here, we present evidence to suggest that this genus, Venenivibrio (phylum Aquificota), is endemic to Aotearoa-New Zealand. A specific environmental niche that increases habitat isolation was identified, with maximal read abundance of Venenivibrio occurring at pH 4-6, 50-70 °C, and low oxidation-reduction potentials. This was further highlighted by genomic and culture-based analyses of the only characterised species for the genus, Venenivibrio stagnispumantis CP.B2T, which confirmed a chemolithoautotrophic metabolism dependent on hydrogen oxidation. While similarity between Venenivibrio populations illustrated that dispersal is not limited across the TVZ, extensive amplicon, metagenomic, and phylogenomic analyses of global microbial communities from DNA sequence databases indicates Venenivibrio is geographically restricted to the Aotearoa-New Zealand archipelago. We conclude that geographic isolation, complemented by physicochemical constraints, has resulted in the establishment of an endemic bacterial genus.

text: A genus in the bacterial phylum Aquificota appears to be endemic to Aotearoa-New Zealand. Allopatric speciation has been difficult to examine among microorganisms, with prior reports of endemism restricted to sub-genus level taxa. Previous microbial community analysis via 16S rRNA gene sequencing of 925 geothermal springs from the Taupō Volcanic Zone (TVZ), Aotearoa-New Zealand, revealed widespread distribution and abundance of a single bacterial genus across 686 of these ecosystems (pH 1.2-9.6 and 17.4-99.8 °C). Here, we present evidence to suggest that this genus, Venenivibrio (phylum Aquificota), is endemic to Aotearoa-New Zealand. A specific environmental niche that increases habitat isolation was identified, with maximal read abundance of Venenivibrio occurring at pH 4-6, 50-70 °C, and low oxidation-reduction potentials. This was further highlighted by genomic and culture-based analyses of the only characterised species for the genus, Venenivibrio stagnispumantis CP.B2T, which confirmed a chemolithoautotrophic metabolism dependent on hydrogen oxidation. While similarity between Venenivibrio populations illustrated that dispersal is not limited across the TVZ, extensive amplicon, metagenomic, and phylogenomic analyses of global microbial communities from DNA sequence databases indicates Venenivibrio is geographically restricted to the Aotearoa-New Zealand archipelago. We conclude that geographic isolation, complemented by physicochemical constraints, has resulted in the establishment of an endemic bacterial genus.

year: 2024-01-02

title: Stratigraphy and development of c. 17 000 year old Lake Maratoto, North Island, New Zealand, with some inferences about postglacial climatic change

authors: Green, John D.

subjects: paleolimnology

abstract: The stratigraphy and geomorphology of Lake Maratoto and its surrounds were investigated as part of a programme of paleolimnological studies based on sediment cores from lakes in northern North Island. Changes in the lake and catchment were inferred from variations in sediment character, the correlation and timing being determined from distinctive tephra layers in the sediments and by radiocarbon dating. Nineteen new C-l4 dates, on gyttja or peat, are reported (old T½, years B.P,): 11 on tephras (Mamaku Ash 6830 ±90. Wk227; Rotoma Ash 8370 ± 90, Wk522; 8350 ± 100, Wk523; Opepe Tephra 9370 ± 210, Wk230; Mangamate Tephra 9700 ± 140, Wk23l; 10000 ± 120, Wk232; Waiohau Ash 12 200 ± 230, Wk233; 12500 ± 190, Wk234; 12450 ± 200, Wk5l5; 12300 ± 190,Wk516; RotoruaAsh 13450 ± 120, Wk511); 5 on the deposition of Hinuera Formation alluvium (16 300 ± 250, Wk239; 16 900 ± 470, Wk240; 17050 ± 200, Wk358; 16200 +360 -340, Wk509; 15 850 ± 130, Wk510); and 3 on basal peat of the Rukuhia bog (10 250 ± 90, Wk114; 15200 ± 130, Wk534; 10600 ± 90, Wk553).
Lake Maratoto originated c. 17 000 years ago when a small valley was dammed by volcanogenic alluvium (Hinuera Formation). From c. 17 000 to c. 14 000 years ago the lake was about 2 m deep with clear water. Marginal peat first developed at c. 15000 years ago, reducing the area of the lake by about one-half by c. 13 000 years ago. Lake area then expanded, possibly because of marginal erosion and/or oxidation of the peat, to its maximum size at the present day. The adjacent Rukuhia peat bog grew rapidly from c. 11 000 years ago and is now 8 m thick immediately to the west of the lake. As a result of this growth, the lake became dystrophic and deepened (3.5 m at c. 7000 years ago, 6.4 m at c. 2000 years ago, and 7. 1 m today).
The developmental history suggests that net precipitation increased at c. 15 000 years ago, increased further at c. 11 000 years ago, remaining high to c. 7000 years ago at least, but with a decline at or before c. 2000 years ago. There may have been a distinctly wetter or windier period from c. 10 000 to 9000 years ago.
This interpretation is consistent with other reconstructions of postglacial climate in the Southern Hemisphere.

text: Stratigraphy and development of c. 17 000 year old Lake Maratoto, North Island, New Zealand, with some inferences about postglacial climatic change The stratigraphy and geomorphology of Lake Maratoto and its surrounds were investigated as part of a programme of paleolimnological studies based on sediment cores from lakes in northern North Island. Changes in the lake and catchment were inferred from variations in sediment character, the correlation and timing being determined from distinctive tephra layers in the sediments and by radiocarbon dating. Nineteen new C-l4 dates, on gyttja or peat, are reported (old T½, years B.P,): 11 on tephras (Mamaku Ash 6830 ±90. Wk227; Rotoma Ash 8370 ± 90, Wk522; 8350 ± 100, Wk523; Opepe Tephra 9370 ± 210, Wk230; Mangamate Tephra 9700 ± 140, Wk23l; 10000 ± 120, Wk232; Waiohau Ash 12 200 ± 230, Wk233; 12500 ± 190, Wk234; 12450 ± 200, Wk5l5; 12300 ± 190,Wk516; RotoruaAsh 13450 ± 120, Wk511); 5 on the deposition of Hinuera Formation alluvium (16 300 ± 250, Wk239; 16 900 ± 470, Wk240; 17050 ± 200, Wk358; 16200 +360 -340, Wk509; 15 850 ± 130, Wk510); and 3 on basal peat of the Rukuhia bog (10 250 ± 90, Wk114; 15200 ± 130, Wk534; 10600 ± 90, Wk553).
Lake Maratoto originated c. 17 000 years ago when a small valley was dammed by volcanogenic alluvium (Hinuera Formation). From c. 17 000 to c. 14 000 years ago the lake was about 2 m deep with clear water. Marginal peat first developed at c. 15000 years ago, reducing the area of the lake by about one-half by c. 13 000 years ago. Lake area then expanded, possibly because of marginal erosion and/or oxidation of the peat, to its maximum size at the present day. The adjacent Rukuhia peat bog grew rapidly from c. 11 000 years ago and is now 8 m thick immediately to the west of the lake. As a result of this growth, the lake became dystrophic and deepened (3.5 m at c. 7000 years ago, 6.4 m at c. 2000 years ago, and 7. 1 m today).
The developmental history suggests that net precipitation increased at c. 15 000 years ago, increased further at c. 11 000 years ago, remaining high to c. 7000 years ago at least, but with a decline at or before c. 2000 years ago. There may have been a distinctly wetter or windier period from c. 10 000 to 9000 years ago.
This interpretation is consistent with other reconstructions of postglacial climate in the Southern Hemisphere.

year: 1985

title: Māori whānau experiences of a neonatal intensive care unit: Waikato hospital

authors: Thompson, Keri

subjects: Maori whanau narratives

abstract: This thesis topic emerged from my personal experience of having a premature baby in the Neonatal Intensive Care Unit (NICU) at Waikato hospital.  My whānau and I felt like aliens; culturally inept, and totally alone during our time in the NICU.  It was not until I spoke to other Māori mothers that I realised our stories were similar.   

I sought to understand how other Māori whānau members made sense of their own experiences, how they coped/adjusted to the experience of having a premature baby in an NICU and at home, and the sources of support they utilised. This study did not seek to delineate parents' experiences but attempted to allow whānau members to share their stories and explore their experiences of having a premature or special-care baby in an NICU.

The event of childbirth and the placing of a natural event into a pathological illness model through necessity has repercussions for the ways in which women experience and make sense of the event.  Knowing this, six whānau stories were collected comprising of four individual interviews with the mothers and two whānau hui (focus groups).  My use of a narrative methodology and kaupapa Māori approach enabled all the participants the opportunity to share their stories on how they make sense of their own experiences without the frame of pathological illness. 

The findings present each whānau story autonomously, to highlight the key events that   occur once the birth of a premature/special-care infant is admitted into an NICU. The participants' narratives followed their transitions through an NICU and return home. The narrative analysis and discussion confirmed that this research had been successful in creating a space for the mothers and their whānau members to share their stories.  The discussion combined their narratives to reveal that the effective coping strategies did not remove the sources of stress but rather lessened the impact of the stresses.  In situations where sources of stress were unable to be removed or reduced, participants perceptions of ineffective coping translated into narratives of negative perceptions of the NICU, and birthing experience. 

The importance of positive relationships within an NICU, and in particular, the role of the nurse as a key facilitator, highlighted that efficacious communication resulted in positive experiences for Māori whānau.  Whānau support was identified as one of the most important coping strategies for mothers in the NICU.  Those participants who were encouraged to maintain connections with whānau members reported more positive experiences overall.

Three levels of implications were identified in this research. Firstly, that the participants'narratives provided a range of coping strategies for future Māori parents and their whānau who enter an NICU.  Secondly, there are implications for NICU policy, and best practice particularly when supporting Māori in an NICU environment.  Lastly, the narratives provided meaningful insights that contribute to gaps in local, national, and international literature.  Overall, I realised that just like me, these mothers, and other whānau members, constructed narratives that are meaningful accounts to be shared with others.

text: Māori whānau experiences of a neonatal intensive care unit: Waikato hospital This thesis topic emerged from my personal experience of having a premature baby in the Neonatal Intensive Care Unit (NICU) at Waikato hospital.  My whānau and I felt like aliens; culturally inept, and totally alone during our time in the NICU.  It was not until I spoke to other Māori mothers that I realised our stories were similar.   

I sought to understand how other Māori whānau members made sense of their own experiences, how they coped/adjusted to the experience of having a premature baby in an NICU and at home, and the sources of support they utilised. This study did not seek to delineate parents' experiences but attempted to allow whānau members to share their stories and explore their experiences of having a premature or special-care baby in an NICU.

The event of childbirth and the placing of a natural event into a pathological illness model through necessity has repercussions for the ways in which women experience and make sense of the event.  Knowing this, six whānau stories were collected comprising of four individual interviews with the mothers and two whānau hui (focus groups).  My use of a narrative methodology and kaupapa Māori approach enabled all the participants the opportunity to share their stories on how they make sense of their own experiences without the frame of pathological illness. 

The findings present each whānau story autonomously, to highlight the key events that   occur once the birth of a premature/special-care infant is admitted into an NICU. The participants' narratives followed their transitions through an NICU and return home. The narrative analysis and discussion confirmed that this research had been successful in creating a space for the mothers and their whānau members to share their stories.  The discussion combined their narratives to reveal that the effective coping strategies did not remove the sources of stress but rather lessened the impact of the stresses.  In situations where sources of stress were unable to be removed or reduced, participants perceptions of ineffective coping translated into narratives of negative perceptions of the NICU, and birthing experience. 

The importance of positive relationships within an NICU, and in particular, the role of the nurse as a key facilitator, highlighted that efficacious communication resulted in positive experiences for Māori whānau.  Whānau support was identified as one of the most important coping strategies for mothers in the NICU.  Those participants who were encouraged to maintain connections with whānau members reported more positive experiences overall.

Three levels of implications were identified in this research. Firstly, that the participants'narratives provided a range of coping strategies for future Māori parents and their whānau who enter an NICU.  Secondly, there are implications for NICU policy, and best practice particularly when supporting Māori in an NICU environment.  Lastly, the narratives provided meaningful insights that contribute to gaps in local, national, and international literature.  Overall, I realised that just like me, these mothers, and other whānau members, constructed narratives that are meaningful accounts to be shared with others.

year: 2009