title: Human activities shape global patterns of decomposition rates in rivers

authors: Tiegs, S.D.

subjects: CELLDEX Consortium‡

abstract: Rivers and streams contribute to global carbon cycling by decomposing immense quantities of terrestrial plant matter. However, decomposition rates are highly variable and large-scale patterns and drivers of this process remain poorly understood. Using a cellulose-based assay to reflect the primary constituent of plant detritus, we generated a predictive model (81% variance explained) for cellulose decomposition rates across 514 globally distributed streams. A large number of variables were important for predicting decomposition, highlighting the complexity of this process at the global scale. Predicted cellulose decomposition rates, when combined with genus-level litter quality attributes, explain published leaf litter decomposition rates with high accuracy (70% variance explained). Our global map provides estimates of rates across vast understudied areas of Earth and reveals rapid decomposition across continental-scale areas dominated by human activities.

text: Human activities shape global patterns of decomposition rates in rivers Rivers and streams contribute to global carbon cycling by decomposing immense quantities of terrestrial plant matter. However, decomposition rates are highly variable and large-scale patterns and drivers of this process remain poorly understood. Using a cellulose-based assay to reflect the primary constituent of plant detritus, we generated a predictive model (81% variance explained) for cellulose decomposition rates across 514 globally distributed streams. A large number of variables were important for predicting decomposition, highlighting the complexity of this process at the global scale. Predicted cellulose decomposition rates, when combined with genus-level litter quality attributes, explain published leaf litter decomposition rates with high accuracy (70% variance explained). Our global map provides estimates of rates across vast understudied areas of Earth and reveals rapid decomposition across continental-scale areas dominated by human activities.

year: 2024

title: Simulating breaking waves using smoothed particle hydrodynamics

authors: Vaughan, G.L.

abstract: Detailed computational modelling of fluid motion in the surf zone (such as under breaking waves) is difficult, because model domains must be long and narrow, and very high resolutions are required to obtain sufficiently detailed simulations. Existing modelling methods have deficiencies: one class of methods are restricted to simulating waves only to the point where the lip of the wave hits the water, while a second class experience significant numerical errors. A third class of methods are the Lagrangian particle-based methods, and while some of these have been applied to simulating breaking waves, their general usefulness for such work is not yet established. 
Here a model is created (named MARIAN) using smoothed particle hydrodynamics (SPH), an example of a Lagrangian particle-based method. This model is tested, and then used to simulate a number of processes relevant to coastal modelling, namely the propagation of waves in a numerical wave tank, the breaking of solitary waves on plane slopes, and the breaking of cnoidal waves over a real bathymetry. From comparisons of the results, merits and demerits in the model and method can be identified, and general conclusions as to how useful the model is for the task can be established. It is found that while some simulations are very good (a bursting dam, for example), and others are average (a seiching basin), some simulations important for work in the coastal zone are not good ( the propagation of waves in a numerical wave tank) and others are very poor (breaking waves). Clearly, there are limits as to what MARIAN can be used to simulate, and what these limits are is not apparent. 
From the model developed in this study it should be concluded that Lagrangian particle-based models designed for simulating breaking waves have shortcomings, and based on this work, other methods would currently be preferred. However other researchers have recently had more success by using variations on the methods employed here. In particular by using better viscosity formulations they resolved breaking waves reasonably well. In the work performed here it was ascertained that some methods used in the literature cause SPH models to fail in enforcing the fundamental principles of physics. While the current state of the model created here is unsatisfactory, there are promising improvements that could be made, and further research is likely to resolve some of the problems discussed here. Topics that would benefit from further research include finding ways to reduce runtimes and increase resolutions (by parallelizing source code, improving algorithms and identifying the free surface), and ways to increase accuracy (improving the quality of kernels employed, including the "missing boundary integrals", and ensuring consistency) while still enforcing the fundamental principles.

text: Simulating breaking waves using smoothed particle hydrodynamics Detailed computational modelling of fluid motion in the surf zone (such as under breaking waves) is difficult, because model domains must be long and narrow, and very high resolutions are required to obtain sufficiently detailed simulations. Existing modelling methods have deficiencies: one class of methods are restricted to simulating waves only to the point where the lip of the wave hits the water, while a second class experience significant numerical errors. A third class of methods are the Lagrangian particle-based methods, and while some of these have been applied to simulating breaking waves, their general usefulness for such work is not yet established. 
Here a model is created (named MARIAN) using smoothed particle hydrodynamics (SPH), an example of a Lagrangian particle-based method. This model is tested, and then used to simulate a number of processes relevant to coastal modelling, namely the propagation of waves in a numerical wave tank, the breaking of solitary waves on plane slopes, and the breaking of cnoidal waves over a real bathymetry. From comparisons of the results, merits and demerits in the model and method can be identified, and general conclusions as to how useful the model is for the task can be established. It is found that while some simulations are very good (a bursting dam, for example), and others are average (a seiching basin), some simulations important for work in the coastal zone are not good ( the propagation of waves in a numerical wave tank) and others are very poor (breaking waves). Clearly, there are limits as to what MARIAN can be used to simulate, and what these limits are is not apparent. 
From the model developed in this study it should be concluded that Lagrangian particle-based models designed for simulating breaking waves have shortcomings, and based on this work, other methods would currently be preferred. However other researchers have recently had more success by using variations on the methods employed here. In particular by using better viscosity formulations they resolved breaking waves reasonably well. In the work performed here it was ascertained that some methods used in the literature cause SPH models to fail in enforcing the fundamental principles of physics. While the current state of the model created here is unsatisfactory, there are promising improvements that could be made, and further research is likely to resolve some of the problems discussed here. Topics that would benefit from further research include finding ways to reduce runtimes and increase resolutions (by parallelizing source code, improving algorithms and identifying the free surface), and ways to increase accuracy (improving the quality of kernels employed, including the "missing boundary integrals", and ensuring consistency) while still enforcing the fundamental principles.

year: 2005

title: Te whakaako i te reo Māori i te kura auraki tuarua i Aotearoa nei: Kei tua o te awe māpere. The teaching of te reo Māori in English-medium secondary schools in New Zealand: Beyond the mask.

authors: Nock, Sophie

subjects: language curricula

abstract: He taonga te reo Māori nō tuawhakarere, nō tuauriuri, whāioio, nā te atua i homai kia poipoia e te iwi Māori hei reo kōrero mō te hunga kaingākau, mō te hunga kāore anō kia whānau noa.  Ahakoa ia he toimaha tonu te hauora o te reo Māori, nā te mahi tūkino (a ētahi).  I roto i ngā tau whā tekau kua ara ake ngā momo rongoā hei whakahauora, hei whakatairanga i te reo Māori, nā, ko Te Kōhanga Reo tērā, ko te Kura Kaupapa Māori tērā, ko Te Wharekura tērā, aha atu, aha atu.  Ka mutu, i te tau 1987 i whakamanahia ai te reo Māori hei reo tūturu o tēnei whenua.  Ahakoa he aha e mea ana te Tāhūhū o te Mātauranga ehara i te mea me whai wāhi te reo Māori hei reo ako i roto i ngā kura tuarua puta noa i te motu.  Engari, ko te raruraru kua whai wāhi kē ētahi atu reo o te ao, kaua ko te reo Māori.  Kāti, i te tau 2009 i tatū ai Te Aho Arataki Marau mō te Ako i Te Reo Māori, ā, ki reira whai wāhi ai te reo Māori.  Nā, ko tā te kura tuarua mahi he tautoko mārika i te reo Māori, mā te whakaako i te reo Māori, e tika ana me pērā, nā te mea, ko te nuinga o ngā tamariki Māori e haere ana ki a ia ako ai.  Mōhio pai i whakapeto ngoi ngā kaiwhakaako reo Māori me te matatau anō o ētahi ki te reo hoki, engari, ki tā te pūrongo rangahau a Te Tari Arotake Mātauranga kīhai i tino eke panuku ngā mahi whakaako.  Ko ngā tino take, ko te whakangungu kaiwhakaako, ko te tautoko me te whakahaere a te kura hoki.

Nō reira, ko te whāinga matua o tēnei rangahau kia tirohia me pēhea e whakaako ai te reo Māori ki te kura tuarua, (kaua i ngā wharekura) i Aotearoa.  Mai i te rau tau tekau mā waru ka tātaria ētahi o ngā kōrero whanake e hāngai pū ana ki te whakaako me te ako i (t)ētahi atu reo, ko ia te wāhanga tuarua.  Whai muri mai i tērā (kei te wāhanga tuatoru) ko ngā patapatai me ngā uiuitanga, ā, ko tā te patapatai he kukume mai i ngā whakapono, i ngā whakaaro, i ngā waiaro o te hunga kaiwhakaako, ko tā te uiuitanga e whakatātūtū i te rētotanga o te kaupapa.  Ka mutu, i whārikihia ngā whakakitenga, ngā whakahoki kōrero ki taua wāhanga.  I te mutunga iho i whakapau kaha ngā kaiwhakaako ki te whakatutuki i ngā mahi, ahakoa ngā piki me ngā heke.  Kei ngā wāhanga e rua (4 & 5) ngā kōrero mō ngā tūmomo rauemi e whakamahia ana e ngā kaiwhakaako, arā, ko ngā momo pukapuka (4) me ngā tūmomo rauemi o te ipurangi nā Te Tāhūhū o te Mātauranga i whakarato (5).  E kī ana ngā whakaputanga, tuatahi, kīhai aua rauemi i tino whakaatu mai i ngā momo whanaketanga i roto i ngā tau whā tekau neke atu mō te whakaako i te reo tuarua, hou rānei, tuarua, kāhore hoki i tino hāngai pū ēnei rauemi ki te Marau mō te Ako i Te Reo Māori i te kura tuarua me te hāngai anō hoki ki te āhua o te whakaako i te reo mā te ‘Communicative Language Teaching’.  Hei whaiwhai ake i ngā rauemi i tātaria ētahi o ngā karaehe reo (te wāhanga 6) mā ngā wehewehetanga matua o te whakaako reo.  Mai i taua tātaritanga i kitea mai ētahi raruraru, tuatahi, kāhore ngā tauira/akonga i whai wāhi ki te kōrero (i roto tonu i te karaehe), tuarua, kāhore e taea te whakawhitiwhiti kōrero ki a rātou anō, tuatoru, kāhore rātou i te mahi tahi anō hoki.  Hei whakakapi ake i tēnei rangahau, kei te wāhanga whakamutunga (7) te whakakaokao mai o ngā whakakitenga katoa, me te whakatakoto o ngā tūtohutanga kia anga whakamua ai. 

It has been acknowledged that te reo Māori is a taonga and, as such, is subject to the protections guaranteed under the terms of Te Tiriti o Waitangi.  Since 1987, it has been an official language of Aotearoa.  Its future is, however, very far from secure and instructed language learning continues to play a significant part in the revitalisation agenda.  Even so, although schools are now required to offer a language other than the language of instruction to pupils in Years 7 to 10, and although over two thirds of Māori students currently attend schools in which English is the main language of instruction, schools are not required to include te reo Māori in their language offering.  In addition, although curriculum guidelines documents for a number of foreign languages have been available for many years, it was not until 2009 that the final version of a curriculum guidelines document for the teaching and learning of te reo Māori in English-medium schools became available.  Furthermore, while there clearly are some extremely competent teachers of the language, Education Review Office (ERO) reports indicate that all is not well so far as the teaching and learning of te reo Māori in English-medium secondary schools is concerned.  The problems identified relate not to teachers' proficiency in the language but to their limited pedagogical knowledge.  As ERO has indicated, this raises questions about the initial training of teachers of te reo Māori and the ways in which all schools manage and support them. 

The overall aim of the research reported here is to investigate the teaching of te reo Māori in English-medium secondary schools in Aotearoa.  Following a critical review of selected literature on developments in the teaching and learning of additional languages since the end of the 18th Century (Chapter 2), there is a report on a survey (involving questionnaire responses and semi-structured interviews) of a sample of teachers of te reo Māori in English-medium secondary schools.  That survey focuses on their educational and linguistic backgrounds and their attitudes and approaches to a range of issues associated with the teaching and learning of the language in school settings (Chapter 3).  Overall, the findings indicate that while these teachers are doing their best to provide a high quality educational experience for their students, they are doing so in the face of a number of significant barriers relating, in particular, to the limited nature of the pre-service training they have received, and the range of additional duties they are expected to perform.  In addition, the survey revealed some concerns about the impact of national assessment on teaching and learning and about the teaching materials and resources that are available.  The next two chapters report on the analysis of a sample of textbooks which are widely used in secondary schools (Chapter 4) and a sample of resources made available by the Ministry of Education (Chapter 5), the main findings being that these are, in the main, (a) inconsistent with both research-based developments in the teaching of additional languages and the expectations relating to communicative language teaching as outlined in the curriculum guidelines, and (b) that these resources do not align with the new curriculum.  The analysis of a sample of lessons taught in secondary schools follows (Chapter 6).  That analysis, conducted in relation to a number of focus points, reveals some significant problems, including the fact that the students were provided with few opportunities to contribute, to interact with one another, and to engage in genuinely communicative activities.  The final chapter (Chapter 7) provides an overview of the findings and includes some suggestions about a possible way forward.

text: Te whakaako i te reo Māori i te kura auraki tuarua i Aotearoa nei: Kei tua o te awe māpere. The teaching of te reo Māori in English-medium secondary schools in New Zealand: Beyond the mask. He taonga te reo Māori nō tuawhakarere, nō tuauriuri, whāioio, nā te atua i homai kia poipoia e te iwi Māori hei reo kōrero mō te hunga kaingākau, mō te hunga kāore anō kia whānau noa.  Ahakoa ia he toimaha tonu te hauora o te reo Māori, nā te mahi tūkino (a ētahi).  I roto i ngā tau whā tekau kua ara ake ngā momo rongoā hei whakahauora, hei whakatairanga i te reo Māori, nā, ko Te Kōhanga Reo tērā, ko te Kura Kaupapa Māori tērā, ko Te Wharekura tērā, aha atu, aha atu.  Ka mutu, i te tau 1987 i whakamanahia ai te reo Māori hei reo tūturu o tēnei whenua.  Ahakoa he aha e mea ana te Tāhūhū o te Mātauranga ehara i te mea me whai wāhi te reo Māori hei reo ako i roto i ngā kura tuarua puta noa i te motu.  Engari, ko te raruraru kua whai wāhi kē ētahi atu reo o te ao, kaua ko te reo Māori.  Kāti, i te tau 2009 i tatū ai Te Aho Arataki Marau mō te Ako i Te Reo Māori, ā, ki reira whai wāhi ai te reo Māori.  Nā, ko tā te kura tuarua mahi he tautoko mārika i te reo Māori, mā te whakaako i te reo Māori, e tika ana me pērā, nā te mea, ko te nuinga o ngā tamariki Māori e haere ana ki a ia ako ai.  Mōhio pai i whakapeto ngoi ngā kaiwhakaako reo Māori me te matatau anō o ētahi ki te reo hoki, engari, ki tā te pūrongo rangahau a Te Tari Arotake Mātauranga kīhai i tino eke panuku ngā mahi whakaako.  Ko ngā tino take, ko te whakangungu kaiwhakaako, ko te tautoko me te whakahaere a te kura hoki.

Nō reira, ko te whāinga matua o tēnei rangahau kia tirohia me pēhea e whakaako ai te reo Māori ki te kura tuarua, (kaua i ngā wharekura) i Aotearoa.  Mai i te rau tau tekau mā waru ka tātaria ētahi o ngā kōrero whanake e hāngai pū ana ki te whakaako me te ako i (t)ētahi atu reo, ko ia te wāhanga tuarua.  Whai muri mai i tērā (kei te wāhanga tuatoru) ko ngā patapatai me ngā uiuitanga, ā, ko tā te patapatai he kukume mai i ngā whakapono, i ngā whakaaro, i ngā waiaro o te hunga kaiwhakaako, ko tā te uiuitanga e whakatātūtū i te rētotanga o te kaupapa.  Ka mutu, i whārikihia ngā whakakitenga, ngā whakahoki kōrero ki taua wāhanga.  I te mutunga iho i whakapau kaha ngā kaiwhakaako ki te whakatutuki i ngā mahi, ahakoa ngā piki me ngā heke.  Kei ngā wāhanga e rua (4 & 5) ngā kōrero mō ngā tūmomo rauemi e whakamahia ana e ngā kaiwhakaako, arā, ko ngā momo pukapuka (4) me ngā tūmomo rauemi o te ipurangi nā Te Tāhūhū o te Mātauranga i whakarato (5).  E kī ana ngā whakaputanga, tuatahi, kīhai aua rauemi i tino whakaatu mai i ngā momo whanaketanga i roto i ngā tau whā tekau neke atu mō te whakaako i te reo tuarua, hou rānei, tuarua, kāhore hoki i tino hāngai pū ēnei rauemi ki te Marau mō te Ako i Te Reo Māori i te kura tuarua me te hāngai anō hoki ki te āhua o te whakaako i te reo mā te ‘Communicative Language Teaching’.  Hei whaiwhai ake i ngā rauemi i tātaria ētahi o ngā karaehe reo (te wāhanga 6) mā ngā wehewehetanga matua o te whakaako reo.  Mai i taua tātaritanga i kitea mai ētahi raruraru, tuatahi, kāhore ngā tauira/akonga i whai wāhi ki te kōrero (i roto tonu i te karaehe), tuarua, kāhore e taea te whakawhitiwhiti kōrero ki a rātou anō, tuatoru, kāhore rātou i te mahi tahi anō hoki.  Hei whakakapi ake i tēnei rangahau, kei te wāhanga whakamutunga (7) te whakakaokao mai o ngā whakakitenga katoa, me te whakatakoto o ngā tūtohutanga kia anga whakamua ai. 

It has been acknowledged that te reo Māori is a taonga and, as such, is subject to the protections guaranteed under the terms of Te Tiriti o Waitangi.  Since 1987, it has been an official language of Aotearoa.  Its future is, however, very far from secure and instructed language learning continues to play a significant part in the revitalisation agenda.  Even so, although schools are now required to offer a language other than the language of instruction to pupils in Years 7 to 10, and although over two thirds of Māori students currently attend schools in which English is the main language of instruction, schools are not required to include te reo Māori in their language offering.  In addition, although curriculum guidelines documents for a number of foreign languages have been available for many years, it was not until 2009 that the final version of a curriculum guidelines document for the teaching and learning of te reo Māori in English-medium schools became available.  Furthermore, while there clearly are some extremely competent teachers of the language, Education Review Office (ERO) reports indicate that all is not well so far as the teaching and learning of te reo Māori in English-medium secondary schools is concerned.  The problems identified relate not to teachers' proficiency in the language but to their limited pedagogical knowledge.  As ERO has indicated, this raises questions about the initial training of teachers of te reo Māori and the ways in which all schools manage and support them. 

The overall aim of the research reported here is to investigate the teaching of te reo Māori in English-medium secondary schools in Aotearoa.  Following a critical review of selected literature on developments in the teaching and learning of additional languages since the end of the 18th Century (Chapter 2), there is a report on a survey (involving questionnaire responses and semi-structured interviews) of a sample of teachers of te reo Māori in English-medium secondary schools.  That survey focuses on their educational and linguistic backgrounds and their attitudes and approaches to a range of issues associated with the teaching and learning of the language in school settings (Chapter 3).  Overall, the findings indicate that while these teachers are doing their best to provide a high quality educational experience for their students, they are doing so in the face of a number of significant barriers relating, in particular, to the limited nature of the pre-service training they have received, and the range of additional duties they are expected to perform.  In addition, the survey revealed some concerns about the impact of national assessment on teaching and learning and about the teaching materials and resources that are available.  The next two chapters report on the analysis of a sample of textbooks which are widely used in secondary schools (Chapter 4) and a sample of resources made available by the Ministry of Education (Chapter 5), the main findings being that these are, in the main, (a) inconsistent with both research-based developments in the teaching of additional languages and the expectations relating to communicative language teaching as outlined in the curriculum guidelines, and (b) that these resources do not align with the new curriculum.  The analysis of a sample of lessons taught in secondary schools follows (Chapter 6).  That analysis, conducted in relation to a number of focus points, reveals some significant problems, including the fact that the students were provided with few opportunities to contribute, to interact with one another, and to engage in genuinely communicative activities.  The final chapter (Chapter 7) provides an overview of the findings and includes some suggestions about a possible way forward.

year: 2014