title: Limited role of climate change in extreme low rainfall associated with southern Madagascar food insecurity, 2019–21

authors: Harrington, Luke J.

abstract: Southern Madagascar recently experienced a severe food security crisis, made significantly worse by well below average rainfall from July 2019 to June 2021. This exceptional drought has affected a region with high pre-existing levels of vulnerability to food insecurity (subsistence agriculture and pastoralism in the region is rain-fed only), while impacts have been compounded further by COVID-19 restrictions and pest infestations. The rainy seasons of both 2019/20 and 2020/21 saw just 60% of normal rainfall across the Grand South region and was estimated as a 1-in-135 year dry event, only surpassed in severity by the devastating drought of 1990–92. Based on a combination of observations and climate modelling, the likelihood of experiencing such poor rains in the region was not significantly increased due to human-caused climate change: while the observations and models combine to indicate a small shift toward more droughts like the 2019–2021 event as a consequence of climate change, these trends remain overwhelmed by natural variability. This result is consistent with previous research, with the Intergovernmental Panel on Climate Change (IPCC)'s Sixth Assessment Report concluding that any perceptible changes in drought will only emerge in this region if global mean temperatures exceed 2 °C above pre-industrial levels.

text: Limited role of climate change in extreme low rainfall associated with southern Madagascar food insecurity, 2019–21 Southern Madagascar recently experienced a severe food security crisis, made significantly worse by well below average rainfall from July 2019 to June 2021. This exceptional drought has affected a region with high pre-existing levels of vulnerability to food insecurity (subsistence agriculture and pastoralism in the region is rain-fed only), while impacts have been compounded further by COVID-19 restrictions and pest infestations. The rainy seasons of both 2019/20 and 2020/21 saw just 60% of normal rainfall across the Grand South region and was estimated as a 1-in-135 year dry event, only surpassed in severity by the devastating drought of 1990–92. Based on a combination of observations and climate modelling, the likelihood of experiencing such poor rains in the region was not significantly increased due to human-caused climate change: while the observations and models combine to indicate a small shift toward more droughts like the 2019–2021 event as a consequence of climate change, these trends remain overwhelmed by natural variability. This result is consistent with previous research, with the Intergovernmental Panel on Climate Change (IPCC)'s Sixth Assessment Report concluding that any perceptible changes in drought will only emerge in this region if global mean temperatures exceed 2 °C above pre-industrial levels.

year: 2022-12-01

title: Hemicellulolytic and cellulolytic functions of the domains of a β-mannanase cloned from Caldicellosiruptor saccharolyticus

authors: Frangos, Tracy

subjects: mannanase

abstract: Various combinations of the four domains of the multifunctional mannanase from Caldicellosiruptor saccharolyticus have been cloned and expressed in Escherichia coli. The four domains comprise two catalytic domains (1 and 4), and two putative cellulose binding domains (2 and 3). Each of the six gene products (Man1, Man123, Man1234, Man23, Man234 and Man4) was partially purified by heat treatment.
The enzymes Man1234, Man123 and Man1 exhibited activity on mannans, and Man1234, Man234 and Man4 exhibited activity on xylan and carboxymethylcellulose (CMC). For the complete enzyme (Man1234) all activities were of the same order of magnitude. Activities were additive against a mixture of mannan and xylan or mannan and CMC (but not xylan and CMC). The expression product Man23 exhibited activity on none of the substrates tested, nor did its presence influence thermostability or significantly reduce the Km value for any of the substrates. However, when expressed in combination with domains 1 or 4 it greatly increased their activity.
We conclude that domain 1 catalyses mannan hydrolysis and domain 4 catalyses xylan and CMC hydrolysis at the same active site: domains 2 and 3 have no obvious function, since they do not reduce substrate Km nor affect thermostability. However, their effect on rates of substrate hydrolysis may indicate a role influencing the conformation of the adjacent catalytic domains.

text: Hemicellulolytic and cellulolytic functions of the domains of a β-mannanase cloned from Caldicellosiruptor saccharolyticus Various combinations of the four domains of the multifunctional mannanase from Caldicellosiruptor saccharolyticus have been cloned and expressed in Escherichia coli. The four domains comprise two catalytic domains (1 and 4), and two putative cellulose binding domains (2 and 3). Each of the six gene products (Man1, Man123, Man1234, Man23, Man234 and Man4) was partially purified by heat treatment.
The enzymes Man1234, Man123 and Man1 exhibited activity on mannans, and Man1234, Man234 and Man4 exhibited activity on xylan and carboxymethylcellulose (CMC). For the complete enzyme (Man1234) all activities were of the same order of magnitude. Activities were additive against a mixture of mannan and xylan or mannan and CMC (but not xylan and CMC). The expression product Man23 exhibited activity on none of the substrates tested, nor did its presence influence thermostability or significantly reduce the Km value for any of the substrates. However, when expressed in combination with domains 1 or 4 it greatly increased their activity.
We conclude that domain 1 catalyses mannan hydrolysis and domain 4 catalyses xylan and CMC hydrolysis at the same active site: domains 2 and 3 have no obvious function, since they do not reduce substrate Km nor affect thermostability. However, their effect on rates of substrate hydrolysis may indicate a role influencing the conformation of the adjacent catalytic domains.

year: 1999-08

title: The Māori language revitalisation agenda and Te Whakapiki Reo and Te Whakapiki i te Reo: Meeting the needs of teachers

authors: Kahukura, Hine

subjects: Te reo Māori

abstract: Since 1994, and under contract to the New Zealand Ministry of Education, the University of Waikato has provided teacher professional development programmes in the context of kaupapa matauranga Māori. Because these programmes are designed to play a role in the Māori language revitalisation agenda as it relates to the teaching and learning of te reo Māori in school contexts, we believe that it is important to share our experiences with others. In this article, we discuss the context in which these programmes are delivered, some of the ways in which they have changed over time, and what we have learned from them.

text: The Māori language revitalisation agenda and Te Whakapiki Reo and Te Whakapiki i te Reo: Meeting the needs of teachers Since 1994, and under contract to the New Zealand Ministry of Education, the University of Waikato has provided teacher professional development programmes in the context of kaupapa matauranga Māori. Because these programmes are designed to play a role in the Māori language revitalisation agenda as it relates to the teaching and learning of te reo Māori in school contexts, we believe that it is important to share our experiences with others. In this article, we discuss the context in which these programmes are delivered, some of the ways in which they have changed over time, and what we have learned from them.

year: 2005