title: Storing carbon in soil. Can we slow a revolving door?

authors: Schipper, Louis A.

abstract: There is no doubt that soils are a vast store of carbon and partially control the carbon dioxide content of the atmosphere. Maintaining soil organic matter is also crucial for production and environmental protection. Land-use change and management practices are central to maintaining soil carbon, because these can both increase and decrease soil carbon. Pasture systems can store large amounts of soil carbon and there may be an opportunity to store more in New Zealand dairy systems with multiple benefits. Active research is investigating approaches to achieve this goal through the New Zealand Agricultural Greenhouse Gas Research Centre.

text: Storing carbon in soil. Can we slow a revolving door? There is no doubt that soils are a vast store of carbon and partially control the carbon dioxide content of the atmosphere. Maintaining soil organic matter is also crucial for production and environmental protection. Land-use change and management practices are central to maintaining soil carbon, because these can both increase and decrease soil carbon. Pasture systems can store large amounts of soil carbon and there may be an opportunity to store more in New Zealand dairy systems with multiple benefits. Active research is investigating approaches to achieve this goal through the New Zealand Agricultural Greenhouse Gas Research Centre.

year: 2012-10

title: Semi-mechanistic modelling in nonlinear regression: a case study

authors: Domijan, Katarina

subjects: statistics

abstract: This paper discusses the use of highly parameterized semi-mechanistic nonlinear models with particular reference to the PARJIB crop response model of Reid (2002)[Yield response to nutrient supply across a wide range of conditions 1. Model derivation. Field Crops Research77, 161–171]. Compared to empirical linear approaches, such models promise improved generality of application but present considerable challenges for estimation. Some success has been achieved with a fitting approach that uses a Levenberg–Marquardt algorithm starting from initial values determined by a genetic algorithm. Attention must be paid, however, to correlations between parameter estimates and an approach is described to identify these based on large simulated datasets. This work illustrates the value for the scientist in exploring the correlation structure in mechanistic or semi-mechanistic models. Such information might be used to reappraise the structure of the model itself, especially if the experimental evidence is not strong enough to allow estimation of a parameter free of assumptions about the values of others. Thus statistical modelling and analysis can complement mechanistic studies, making more explicit what is known and what is not known about the processes being modelled and guiding further research.

text: Semi-mechanistic modelling in nonlinear regression: a case study This paper discusses the use of highly parameterized semi-mechanistic nonlinear models with particular reference to the PARJIB crop response model of Reid (2002)[Yield response to nutrient supply across a wide range of conditions 1. Model derivation. Field Crops Research77, 161–171]. Compared to empirical linear approaches, such models promise improved generality of application but present considerable challenges for estimation. Some success has been achieved with a fitting approach that uses a Levenberg–Marquardt algorithm starting from initial values determined by a genetic algorithm. Attention must be paid, however, to correlations between parameter estimates and an approach is described to identify these based on large simulated datasets. This work illustrates the value for the scientist in exploring the correlation structure in mechanistic or semi-mechanistic models. Such information might be used to reappraise the structure of the model itself, especially if the experimental evidence is not strong enough to allow estimation of a parameter free of assumptions about the values of others. Thus statistical modelling and analysis can complement mechanistic studies, making more explicit what is known and what is not known about the processes being modelled and guiding further research.

year: 2006

title: Māori Women and Gambling: Every Day is a War Day!

authors: Morrison, Laurie Elena

subjects: Maori

abstract: This study was concerned with the health implications of new forms of gambling such as casinos, pokie machines and internet gambling for Māori women and their families in Auckland and the Bay of Plenty region of Aotearoa (New Zealand). It set out to discover what culturally appropriate services were available and the extent to which Māori women gamblers were utilising them. The literature documenting Māori perceptions of gambling shows that Māori women gamblers and their partner/whānau members and gambling service providers have been little studied previously.
These goals translated into the following specific aims: 1) to study how Māori women problem gamblers, their partner or whānau members and key informants perceived gambling, what it meant to them and why they did it; 2) to investigate the consequences of gambling for Māori women, whānau and service providers in dealing with the effects of gambling; 3) to report on how these three groups dealt with the effects of gambling; and 4) to discover what helped to bring about positive changes for the three groups.
 All of the aims were achieved. 
A Māori approach (Kaupapa Māori), combined with a naturalistic approach to data collection, was adopted. Qualitative methods are most appropriate to use when working with some Māori, as there is a growing realisation that research with Māori needs to be interactive. A Māori research procedure modelled on the ritual ceremony of encounter (Pōwhiri) provided an appropriate structure for the development and presentation of the research process. The major focus was on the qualitative data obtained from semi-structured interviews in two locations - Rotorua and Auckland. The interviews were conducted with twenty Māori women gamblers, sixteen whānau members including partners and ten interviews with staff involved in services that provided help for problem gamblers. The three interview schedules were based on a number of broad themes and open-ended questions to obtain meaningful descriptive data. The interviews were audio recorded and used to produce transcripts that were then sent back to the participants for feedback. Qualitative data analysis was conducted on the returned documents. 
The findings from this study revealed major impacts of the women's socio-economic, familial and societal circumstances on gambling behaviour and its effects, which are areas of concern for mental health professionals and researchers. The mythical Māori canoes on which Māori voyaged from their place of origin (Hawaiiki) to Aotearoa, the Waka, provided an appropriate metaphor to present the interrelationship between the pull and push factors toward gambling, and its implications for society. This is illustrated as a spinning waka, Te Waka Hūrihuri. On the other hand, Te Waka Māia (courageous) demonstrates the relationships between the variables that help Māori women gamblers to cope and helpful strategies found to assist them to modify or stop their gambling behaviour. It is recommended that the government limit the proliferation of gaming venues and continue to encourage development of emerging Māori services. Moreover, a coordinated approach is essential, as Māori women gamblers, partners and whānau members need to heal together for positive outcomes for Māori health development in Aotearoa. 
The main implication of this study is that a wide range of further research into Māori and gambling is required. Recommendations on ways in which the current delivery of services in Rotorua and Auckland could be improved are:
 	That the Ministry of Health purchase services that establish support groups for Māori people with problem gambling and their whānau, and
 	That non-Māori provider services and organisations support the development of emerging Māori services.
Heeding the outcome of this research should help improve New Zealand's existing health policy and capacity for Māori women's health development. It should also enrich our understanding of the adaptation patterns of Māori whānau member/s, and thus should have implications, not only for Māori health policies, but also relevance for the wider field of international cross-comparative research on indigenous gambling and mental health issues.  Limitations of this study included a small, localised sample that means the findings can only tentatively be generalised to the wider population of Māori women gamblers. Nonetheless, information gained from the study contributes to understanding of the adaptation patterns of Māori women gamblers, their whānau member/s, and those who are trying to help them.  It is hoped that the study will make it at least a little less true that  every day is a war day  for Māori women and their whānau trying to deal with the problem of gambling.

text: Māori Women and Gambling: Every Day is a War Day! This study was concerned with the health implications of new forms of gambling such as casinos, pokie machines and internet gambling for Māori women and their families in Auckland and the Bay of Plenty region of Aotearoa (New Zealand). It set out to discover what culturally appropriate services were available and the extent to which Māori women gamblers were utilising them. The literature documenting Māori perceptions of gambling shows that Māori women gamblers and their partner/whānau members and gambling service providers have been little studied previously.
These goals translated into the following specific aims: 1) to study how Māori women problem gamblers, their partner or whānau members and key informants perceived gambling, what it meant to them and why they did it; 2) to investigate the consequences of gambling for Māori women, whānau and service providers in dealing with the effects of gambling; 3) to report on how these three groups dealt with the effects of gambling; and 4) to discover what helped to bring about positive changes for the three groups.
 All of the aims were achieved. 
A Māori approach (Kaupapa Māori), combined with a naturalistic approach to data collection, was adopted. Qualitative methods are most appropriate to use when working with some Māori, as there is a growing realisation that research with Māori needs to be interactive. A Māori research procedure modelled on the ritual ceremony of encounter (Pōwhiri) provided an appropriate structure for the development and presentation of the research process. The major focus was on the qualitative data obtained from semi-structured interviews in two locations - Rotorua and Auckland. The interviews were conducted with twenty Māori women gamblers, sixteen whānau members including partners and ten interviews with staff involved in services that provided help for problem gamblers. The three interview schedules were based on a number of broad themes and open-ended questions to obtain meaningful descriptive data. The interviews were audio recorded and used to produce transcripts that were then sent back to the participants for feedback. Qualitative data analysis was conducted on the returned documents. 
The findings from this study revealed major impacts of the women's socio-economic, familial and societal circumstances on gambling behaviour and its effects, which are areas of concern for mental health professionals and researchers. The mythical Māori canoes on which Māori voyaged from their place of origin (Hawaiiki) to Aotearoa, the Waka, provided an appropriate metaphor to present the interrelationship between the pull and push factors toward gambling, and its implications for society. This is illustrated as a spinning waka, Te Waka Hūrihuri. On the other hand, Te Waka Māia (courageous) demonstrates the relationships between the variables that help Māori women gamblers to cope and helpful strategies found to assist them to modify or stop their gambling behaviour. It is recommended that the government limit the proliferation of gaming venues and continue to encourage development of emerging Māori services. Moreover, a coordinated approach is essential, as Māori women gamblers, partners and whānau members need to heal together for positive outcomes for Māori health development in Aotearoa. 
The main implication of this study is that a wide range of further research into Māori and gambling is required. Recommendations on ways in which the current delivery of services in Rotorua and Auckland could be improved are:
 	That the Ministry of Health purchase services that establish support groups for Māori people with problem gambling and their whānau, and
 	That non-Māori provider services and organisations support the development of emerging Māori services.
Heeding the outcome of this research should help improve New Zealand's existing health policy and capacity for Māori women's health development. It should also enrich our understanding of the adaptation patterns of Māori whānau member/s, and thus should have implications, not only for Māori health policies, but also relevance for the wider field of international cross-comparative research on indigenous gambling and mental health issues.  Limitations of this study included a small, localised sample that means the findings can only tentatively be generalised to the wider population of Māori women gamblers. Nonetheless, information gained from the study contributes to understanding of the adaptation patterns of Māori women gamblers, their whānau member/s, and those who are trying to help them.  It is hoped that the study will make it at least a little less true that  every day is a war day  for Māori women and their whānau trying to deal with the problem of gambling.

year: 2008