title: Neurobeachin, a regulator of synaptic protein targeting, is associated with body fat mass and feeding behavior in mice and body-mass index in humans

authors: Olszewski, Pawel K.

subjects: ioenergetics

abstract: Neurobeachin (Nbea) regulates neuronal membrane protein trafficking and is required for the development and functioning of central and neuromuscular synapses. In homozygous knockout (KO) mice, Nbea deficiency causes perinatal death. Here, we report that heterozygous KO mice haploinsufficient for Nbea have higher body weight due to increased adipose tissue mass. In several feeding paradigms, heterozygous KO mice consumed more food than wild-type (WT) controls, and this consumption was primarily driven by calories rather than palatability. Expression analysis of feeding-related genes in the hypothalamus and brainstem with real-time PCR showed differential expression of a subset of neuropeptide or neuropeptide receptor mRNAs between WT and Nbea+/− mice in the sated state and in response to food deprivation, but not to feeding reward. In humans, we identified two intronic NBEA single-nucleotide polymorphisms (SNPs) that are significantly associated with body-mass index (BMI) in adult and juvenile cohorts. Overall, data obtained in mice and humans suggest that variation of Nbea abundance or activity critically affects body weight, presumably by influencing the activity of feeding-related neural circuits. Our study emphasizes the importance of neural mechanisms in body weight control and points out NBEA as a potential risk gene in human obesity.

text: Neurobeachin, a regulator of synaptic protein targeting, is associated with body fat mass and feeding behavior in mice and body-mass index in humans Neurobeachin (Nbea) regulates neuronal membrane protein trafficking and is required for the development and functioning of central and neuromuscular synapses. In homozygous knockout (KO) mice, Nbea deficiency causes perinatal death. Here, we report that heterozygous KO mice haploinsufficient for Nbea have higher body weight due to increased adipose tissue mass. In several feeding paradigms, heterozygous KO mice consumed more food than wild-type (WT) controls, and this consumption was primarily driven by calories rather than palatability. Expression analysis of feeding-related genes in the hypothalamus and brainstem with real-time PCR showed differential expression of a subset of neuropeptide or neuropeptide receptor mRNAs between WT and Nbea+/− mice in the sated state and in response to food deprivation, but not to feeding reward. In humans, we identified two intronic NBEA single-nucleotide polymorphisms (SNPs) that are significantly associated with body-mass index (BMI) in adult and juvenile cohorts. Overall, data obtained in mice and humans suggest that variation of Nbea abundance or activity critically affects body weight, presumably by influencing the activity of feeding-related neural circuits. Our study emphasizes the importance of neural mechanisms in body weight control and points out NBEA as a potential risk gene in human obesity.

year: 2012

title: The effects of terrestrial sediment inputs on ecosystem functions in seagrass meadows and unvegetated sediments

authors: Flowers, Georgina

subjects: seagrass

abstract: Ecological functions in estuarine seagrass and unvegetated soft sediment habitats underpin many valuable ecosystem services. However, changing land-use and climate are accelerating inputs of fine terrestrial sediments, threatening these habitats. The prolonged suspension of fine sediments can reduce seafloor light availability and long-term accumulations increase sediment mud content (particles < 63 µm), both of which could have significant consequences on ecosystem functioning. Understanding how ecosystem functioning may respond to environmental change is vital to estuary management. In this thesis, I investigated the short- and long-term effects of elevated terrestrial sediment inputs on benthic primary production and nutrient cycling in intertidal seagrass meadows (Zostera muelleri) and microphytobenthos-dominated unvegetated habitats. 
To investigate the effects of reduced seafloor light availability and prolonged submergence periods resulting from global heating induced sea-level rise, I conducted a two-year seasonal in situ assessment of photosynthesis-irradiance relationships during submerged and emerged conditions in an adjacent seagrass meadow and unvegetated sandflat. Submerged gross primary production (GPP) in both habitats and emerged GPP in the seagrass habitat were strongly controlled by light availability. Higher rates of light-saturated GPP were found during submerged periods compared to emerged periods in both habitats, but this difference was most pronounced in the unvegetated habitat. If the water-column remains clear, sea-level rise could therefore increase daily GPP in soft sediment habitats. However, declines in submerged GPP with increased water-column turbidity will be exacerbated with sea-level rise. 
Across a natural mud content gradient, I measured primary production in seagrass and unvegetated habitats to address the long-term implications of elevated sediment inputs. In sediments with ≤ 35 % mud content, net primary production (NPP) and GPP was independent of mud content in both habitats. However, extending the mud gradient in unvegetated habitats to 49 % (seagrass habitats restricted to ≤ 35 % mud content) resulted in NPP and GPP declining with increasing mud content. These results highlight that loss of seagrass meadows resulting in expansion of unvegetated habitats could lead to reductions in intertidal production; seen most acutely in areas with high mud content (≥ 39 %).
I also investigated the spatial and temporal variability in nutrient cycling in seagrass and unvegetated habitats to examine how environmental gradients affected sediment nutrient fluxes and denitrification rates. Ammonium effluxes were lower in the seagrass compared to the unvegetated habitats and were lower in both habitats during light compared to dark conditions. Denitrification rates were similar in both habitats but were found to decrease with increasing mud content. Overall, denitrification efficiency was highest in the seagrass habitat. These results indicate that future seagrass decline and/or increased mud content in soft sediment habitats will reduce resilience to eutrophication. 
This thesis demonstrates that future seagrass decline and elevated terrestrial sediment inputs are likely to have serious implications on the high rates of primary production and nutrient cycling of intertidal seagrass meadows and unvegetated habitats. Furthermore, it highlights the value of measuring ecosystem functions in different soft sediment habitat types across multiple spatial and temporal scales to inform future management against anthropogenic stressors.

text: The effects of terrestrial sediment inputs on ecosystem functions in seagrass meadows and unvegetated sediments Ecological functions in estuarine seagrass and unvegetated soft sediment habitats underpin many valuable ecosystem services. However, changing land-use and climate are accelerating inputs of fine terrestrial sediments, threatening these habitats. The prolonged suspension of fine sediments can reduce seafloor light availability and long-term accumulations increase sediment mud content (particles < 63 µm), both of which could have significant consequences on ecosystem functioning. Understanding how ecosystem functioning may respond to environmental change is vital to estuary management. In this thesis, I investigated the short- and long-term effects of elevated terrestrial sediment inputs on benthic primary production and nutrient cycling in intertidal seagrass meadows (Zostera muelleri) and microphytobenthos-dominated unvegetated habitats. 
To investigate the effects of reduced seafloor light availability and prolonged submergence periods resulting from global heating induced sea-level rise, I conducted a two-year seasonal in situ assessment of photosynthesis-irradiance relationships during submerged and emerged conditions in an adjacent seagrass meadow and unvegetated sandflat. Submerged gross primary production (GPP) in both habitats and emerged GPP in the seagrass habitat were strongly controlled by light availability. Higher rates of light-saturated GPP were found during submerged periods compared to emerged periods in both habitats, but this difference was most pronounced in the unvegetated habitat. If the water-column remains clear, sea-level rise could therefore increase daily GPP in soft sediment habitats. However, declines in submerged GPP with increased water-column turbidity will be exacerbated with sea-level rise. 
Across a natural mud content gradient, I measured primary production in seagrass and unvegetated habitats to address the long-term implications of elevated sediment inputs. In sediments with ≤ 35 % mud content, net primary production (NPP) and GPP was independent of mud content in both habitats. However, extending the mud gradient in unvegetated habitats to 49 % (seagrass habitats restricted to ≤ 35 % mud content) resulted in NPP and GPP declining with increasing mud content. These results highlight that loss of seagrass meadows resulting in expansion of unvegetated habitats could lead to reductions in intertidal production; seen most acutely in areas with high mud content (≥ 39 %).
I also investigated the spatial and temporal variability in nutrient cycling in seagrass and unvegetated habitats to examine how environmental gradients affected sediment nutrient fluxes and denitrification rates. Ammonium effluxes were lower in the seagrass compared to the unvegetated habitats and were lower in both habitats during light compared to dark conditions. Denitrification rates were similar in both habitats but were found to decrease with increasing mud content. Overall, denitrification efficiency was highest in the seagrass habitat. These results indicate that future seagrass decline and/or increased mud content in soft sediment habitats will reduce resilience to eutrophication. 
This thesis demonstrates that future seagrass decline and elevated terrestrial sediment inputs are likely to have serious implications on the high rates of primary production and nutrient cycling of intertidal seagrass meadows and unvegetated habitats. Furthermore, it highlights the value of measuring ecosystem functions in different soft sediment habitat types across multiple spatial and temporal scales to inform future management against anthropogenic stressors.

year: 2024-04-15

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