title: River Mouth Processes and Morphodynamics on a Mixed Sand-Gravel Beach

authors: Paterson, Adam Karl

subjects: Ashburton river

abstract: Where the Ashburton river meets the sea it is impounded by a mixed sand-gravel barrier, formed through littoral transport of sediment, causing a lagoon to form, locally referred to as hapua. From the hapua, discharge to the sea is maintained through small, ephemeral channels, which are unstable and are subject to morphological change in response to fluctuations in longshore transport of gravel and variations in river flow rate. There are few descriptions of the morphodynamics of these highly changeable features, particularly changes that occur over short time scales of hours to weeks.
To investigate the patterns and processes involved in the migration of drainage channels, several new instruments were trialed. A methodology of was developed to provide estimates of longshore transport on a gravel beach using a Gravel Transport Sensor. Video camera technology was the primary tool used to study river mouth morphodynamics. The camera provided hourly images of the environment, enabling qualitative assessment using movies of the images to observe morphologic changes, and quantitative measurement of the migration of the channel. Measurements of river flow, wave climate and lagoon water levels were also gathered to investigate the relationships between the morphological response and the forcing factors.
Results of the study showed that the ends of the channel behave differently, with the lagoon end remaining more stable than the seaward end. The seaward end is more exposed to the high wave energy prevalent along this coast. The wave climate, especially wave period and direction, were found to be predictors for the migration rate. The location of the seaward end is more variable due to the fluctuations in wave climate, differing from the lagoon end which is influenced predominantly by river flow rates. It has been found that the migration of the lagoon end occurs in 'steps', which are separated by raised gravel banks, the single persistent feature throughout the study. This stepping migration is driven primarily through episodic events such as high river flow or large wave events.

text: River Mouth Processes and Morphodynamics on a Mixed Sand-Gravel Beach Where the Ashburton river meets the sea it is impounded by a mixed sand-gravel barrier, formed through littoral transport of sediment, causing a lagoon to form, locally referred to as hapua. From the hapua, discharge to the sea is maintained through small, ephemeral channels, which are unstable and are subject to morphological change in response to fluctuations in longshore transport of gravel and variations in river flow rate. There are few descriptions of the morphodynamics of these highly changeable features, particularly changes that occur over short time scales of hours to weeks.
To investigate the patterns and processes involved in the migration of drainage channels, several new instruments were trialed. A methodology of was developed to provide estimates of longshore transport on a gravel beach using a Gravel Transport Sensor. Video camera technology was the primary tool used to study river mouth morphodynamics. The camera provided hourly images of the environment, enabling qualitative assessment using movies of the images to observe morphologic changes, and quantitative measurement of the migration of the channel. Measurements of river flow, wave climate and lagoon water levels were also gathered to investigate the relationships between the morphological response and the forcing factors.
Results of the study showed that the ends of the channel behave differently, with the lagoon end remaining more stable than the seaward end. The seaward end is more exposed to the high wave energy prevalent along this coast. The wave climate, especially wave period and direction, were found to be predictors for the migration rate. The location of the seaward end is more variable due to the fluctuations in wave climate, differing from the lagoon end which is influenced predominantly by river flow rates. It has been found that the migration of the lagoon end occurs in 'steps', which are separated by raised gravel banks, the single persistent feature throughout the study. This stepping migration is driven primarily through episodic events such as high river flow or large wave events.

year: 2000

title: Effect of Body Condition Score at Calving on Adaptive Immune Function During Early Lactation in New Zealand Dairy Cows: Effect of calving body condition on adaptive immune function

authors: McGowan, Jacqueline Ellen

subjects: Candida albicans

abstract: The extent of postpartum negative energy balance in dairy cows is positively associated with body condition score (BCS) at calving. Results of epidemiological studies have indicated that calving BCS is positively correlated with several indicators of immune dysfunction during the post-partum period. Metabolites of negative energy balance (NEB) have been associated with impaired lymphocyte and neutrophil function in vitro. Therefore, cows that calve in greater condition might exhibit a greater degree of periparturient immune dysfunction than thinner cows.
The objective of this thesis was to investigate the effect of BCS at calving on adaptive immune function, using in vivo measures. Two experiments were conducted using dairy cows in the DairyNZ Lye farm herd.
The first experiment determined the level of background exposure to Candida albicans. Delayed-type hypersensitivity (DTH) to C. albicans is used as an indicator of cell-mediated immune response (CMIR) in cattle. Prior immunisation against C. albicans ensures measurable DTH responses from most cows. However, if natural exposure to C. albicans is high or variable, background DTH must be measured before immunisation, or an alternate antigen used. To determine background DTH responses in pasture-based cows, responses of ten unimmunised and ten immunised cows were compared. A greater proportion of immunised versus unimmunised cows mounted a positive DTH response (90% vs. 70%), and responses were larger (P < 0.01) and more variable (P < 0.05) in immunised cows. Results indicate that pasture-based cows in New Zealand have consistently low background exposure to C. albicans. Therefore, C. albicans is an appropriate antigen for inducing DTH responses as an in vivo measure of CMIR in pasture-based cows.
The second experiment tested the hypothesis that BCS at calving affects immune function. The energy balance of sixty healthy cows with similar mid-lactation BCS was manipulated in late-lactation to achieve three homogenous BCS groups of twenty cows at calving, with calving BCS of 3.4, 4.6 and 5.4 (NZ BCS scale of 1 to 10). Antibody-mediated immune responses (AMIR) and cell-mediated immune responses (CMIR) measured postpartum were compared with responses measured in mid-lactation before BCS manipulation began. Calving BCS had no effect on the magnitude of AMIR (P = 0.93) or CMIR (P = 0.99), and did not affect the ratio of antigen-specific IgG1 and IgG2 produced during AMIR (P = 0.48). These results indicate that, within the range of BCS at calving investigated, and the associated degree of postpartum NEB did not influence ability to mount adaptive immune responses in vivo.
Cows calving within the BCS range examined (between 3.4 and 5.4) did not differ in AMIR or CMIR; therefore, the results support the current recommendations regarding optimal calving BCS for mature cows, and support the minimum BCS allowed by the welfare code.

text: Effect of Body Condition Score at Calving on Adaptive Immune Function During Early Lactation in New Zealand Dairy Cows: Effect of calving body condition on adaptive immune function The extent of postpartum negative energy balance in dairy cows is positively associated with body condition score (BCS) at calving. Results of epidemiological studies have indicated that calving BCS is positively correlated with several indicators of immune dysfunction during the post-partum period. Metabolites of negative energy balance (NEB) have been associated with impaired lymphocyte and neutrophil function in vitro. Therefore, cows that calve in greater condition might exhibit a greater degree of periparturient immune dysfunction than thinner cows.
The objective of this thesis was to investigate the effect of BCS at calving on adaptive immune function, using in vivo measures. Two experiments were conducted using dairy cows in the DairyNZ Lye farm herd.
The first experiment determined the level of background exposure to Candida albicans. Delayed-type hypersensitivity (DTH) to C. albicans is used as an indicator of cell-mediated immune response (CMIR) in cattle. Prior immunisation against C. albicans ensures measurable DTH responses from most cows. However, if natural exposure to C. albicans is high or variable, background DTH must be measured before immunisation, or an alternate antigen used. To determine background DTH responses in pasture-based cows, responses of ten unimmunised and ten immunised cows were compared. A greater proportion of immunised versus unimmunised cows mounted a positive DTH response (90% vs. 70%), and responses were larger (P < 0.01) and more variable (P < 0.05) in immunised cows. Results indicate that pasture-based cows in New Zealand have consistently low background exposure to C. albicans. Therefore, C. albicans is an appropriate antigen for inducing DTH responses as an in vivo measure of CMIR in pasture-based cows.
The second experiment tested the hypothesis that BCS at calving affects immune function. The energy balance of sixty healthy cows with similar mid-lactation BCS was manipulated in late-lactation to achieve three homogenous BCS groups of twenty cows at calving, with calving BCS of 3.4, 4.6 and 5.4 (NZ BCS scale of 1 to 10). Antibody-mediated immune responses (AMIR) and cell-mediated immune responses (CMIR) measured postpartum were compared with responses measured in mid-lactation before BCS manipulation began. Calving BCS had no effect on the magnitude of AMIR (P = 0.93) or CMIR (P = 0.99), and did not affect the ratio of antigen-specific IgG1 and IgG2 produced during AMIR (P = 0.48). These results indicate that, within the range of BCS at calving investigated, and the associated degree of postpartum NEB did not influence ability to mount adaptive immune responses in vivo.
Cows calving within the BCS range examined (between 3.4 and 5.4) did not differ in AMIR or CMIR; therefore, the results support the current recommendations regarding optimal calving BCS for mature cows, and support the minimum BCS allowed by the welfare code.

year: 2014

title: A Māori and Pacific lens on infant and toddler provision in early childhood education

authors: Rameka, Lesley Kay

abstract: While New Zealand has made major advances in educational provision, Mäori and Pacific chil- dren continue to lag behind other groups, achieving disproportionately lower results on national averages (Marriot & Sim, 2014). Key to educational success for Mäori and Pasifika children is the acknowledgement that they are culturally located and the recognition that effective education must embrace culture. Early childhood education has an important role in building strong learn- ing foundations for young children; however, achieving this is a complex process, especially with regard to Mäori and Pacific children in early childhood education. This article outlines findings from a 2014 nationwide online survey conducted with Mäori and Pacific teachers working in Mäori and Pacific early childhood services and language nests. Respondents were asked about traditional and contemporary caregiving practices for infants and toddlers and what barriers and enablers were faced in implementing these caregiving practices within their services.

text: A Māori and Pacific lens on infant and toddler provision in early childhood education While New Zealand has made major advances in educational provision, Mäori and Pacific chil- dren continue to lag behind other groups, achieving disproportionately lower results on national averages (Marriot & Sim, 2014). Key to educational success for Mäori and Pasifika children is the acknowledgement that they are culturally located and the recognition that effective education must embrace culture. Early childhood education has an important role in building strong learn- ing foundations for young children; however, achieving this is a complex process, especially with regard to Mäori and Pacific children in early childhood education. This article outlines findings from a 2014 nationwide online survey conducted with Mäori and Pacific teachers working in Mäori and Pacific early childhood services and language nests. Respondents were asked about traditional and contemporary caregiving practices for infants and toddlers and what barriers and enablers were faced in implementing these caregiving practices within their services.

year: 2015