title: On the ecogeomorphological feedbacks that control tidal channel network evolution in a sandy mangrove setting

authors: van Maanen, Barend

subjects: tidal channel networks, mangroves,

abstract: An ecomorphodynamic model was developed to study how Avicennia marina mangroves influence channel network evolution in sandy tidal embayments. The model accounts for the effects of mangrove trees on tidal flow patterns and sediment dynamics. Mangrove growth is in turn controlled by hydrodynamic conditions. The presence of mangroves was found to enhance the initiation and branching of tidal channels, partly because the extra flow resistance in mangrove forests favours flow concentration, and thus sediment erosion in between vegetated areas. The enhanced branching of channels is also the result of a vegetation-induced increase in erosion threshold. On the other hand, this reduction in bed erodibility, together with the soil expansion driven by organic matter production, reduces the landward expansion of channels. The ongoing accretion in mangrove forests ultimately drives a reduction in tidal prism and an overall retreat of the channel network. During sea-level rise, mangroves can potentially enhance the ability of the soil surface to maintain an elevation within the upper portion of the intertidal zone, while hindering both the branching and headward erosion of the landward expanding channels. The modelling results presented here indicate the critical control exerted by ecogeomorphological interactions in driving landscape evolution.

text: On the ecogeomorphological feedbacks that control tidal channel network evolution in a sandy mangrove setting An ecomorphodynamic model was developed to study how Avicennia marina mangroves influence channel network evolution in sandy tidal embayments. The model accounts for the effects of mangrove trees on tidal flow patterns and sediment dynamics. Mangrove growth is in turn controlled by hydrodynamic conditions. The presence of mangroves was found to enhance the initiation and branching of tidal channels, partly because the extra flow resistance in mangrove forests favours flow concentration, and thus sediment erosion in between vegetated areas. The enhanced branching of channels is also the result of a vegetation-induced increase in erosion threshold. On the other hand, this reduction in bed erodibility, together with the soil expansion driven by organic matter production, reduces the landward expansion of channels. The ongoing accretion in mangrove forests ultimately drives a reduction in tidal prism and an overall retreat of the channel network. During sea-level rise, mangroves can potentially enhance the ability of the soil surface to maintain an elevation within the upper portion of the intertidal zone, while hindering both the branching and headward erosion of the landward expanding channels. The modelling results presented here indicate the critical control exerted by ecogeomorphological interactions in driving landscape evolution.

year: 2015-06-23

title: The effects of delay to reinforcement and inter-trial interval on fixed-ratio schedule performance

authors: Stuart, Stacey Louisa

abstract: A delay to reinforcement has been found in previous studies to influence the effectiveness of a reinforcer. As the delay duration increases, response rates decrease and post reinforcement pause durations increase. The present study tested whether it was the increase in time between the effective response and delivery of reinforcement, or, the increases in intervals between reinforcers that devalue the reinforcer. This study also compared the ability of two demand equations and MPR to predict response rates when effort required was changed. The effects of varying delay to reinforcement and intertrial interval on behaviour was examined while the time available for responding was kept constant. 
	There were four conditions; 4-s ITI, 4-s delay, 16-s ITI and 16-s delay, and 6 hens responded under each of these conditions in an ascending geometric series of fixed ratio (FR) values. It was shown that hens generally responded at a faster rate in the ITI conditions than the equivalent delay conditions and peak response rates were seen highest in the 16-s ITI condition in accordance with the demand data.  The data was described well by both the demand equations and the MPR equation. While there were inconsistencies among the parameters, there was a moderately strong positive relationships between the parameter values of as and α in the 16-s ITI (r = .51, p = 0.29) and delay (r = .44, p = .44) conditions.

text: The effects of delay to reinforcement and inter-trial interval on fixed-ratio schedule performance A delay to reinforcement has been found in previous studies to influence the effectiveness of a reinforcer. As the delay duration increases, response rates decrease and post reinforcement pause durations increase. The present study tested whether it was the increase in time between the effective response and delivery of reinforcement, or, the increases in intervals between reinforcers that devalue the reinforcer. This study also compared the ability of two demand equations and MPR to predict response rates when effort required was changed. The effects of varying delay to reinforcement and intertrial interval on behaviour was examined while the time available for responding was kept constant. 
	There were four conditions; 4-s ITI, 4-s delay, 16-s ITI and 16-s delay, and 6 hens responded under each of these conditions in an ascending geometric series of fixed ratio (FR) values. It was shown that hens generally responded at a faster rate in the ITI conditions than the equivalent delay conditions and peak response rates were seen highest in the 16-s ITI condition in accordance with the demand data.  The data was described well by both the demand equations and the MPR equation. While there were inconsistencies among the parameters, there was a moderately strong positive relationships between the parameter values of as and α in the 16-s ITI (r = .51, p = 0.29) and delay (r = .44, p = .44) conditions.

year: 2013

title: Te kū o te kupu

authors: Raerino, Heddell Robert

subjects: Māori language

abstract: Ko tēnei tuhingaroa, he rangahau hai wherawhera ake i te āhuatanga o te reo Māori, e kiia ana ko tōna oro, me te kū o ngā kupu kōrero o taua reo. Ko te aronga whakaaro o tēnei rangahau, he rapu i tētahi āhuatanga kāore anō kia tirotirohia, kia tuhia rānei mō te reo Māori. Ehara tēnei rangahau i te kaupapa, i te mahi hou. Otirā, kai te whai te kaituhi i ngā rangahau kua oti kē i wētahi tohunga te wānanga mō wētahi atu reo. Ko tā te kaituhi he whai i ngā tauira a te hunga wetewete reo nei, ka uwhi ai ki runga i te reo Māori hai āwhina i ngā tātaritanga ā te kaituhi mō tōna ake reo, arā, te reo Māori.

Kai te upoko tuatahi ka whaia ngā rerenga whakaaro i pūpū ake ai te taitara 'te kū o te kupu' mō tēnei mahi rangahau. Inā ka tirohia i ahu ngā oro o te reo mai i whea e ai ki tā te Māori wānanga. Mai i ngā oro ka puta ko ngā ku o ngā kupu me ngā kupu o ngā rārangi kōrero.

Hai te upoko tuarua ka tirohia ngā kōrero kua tuhia e ngā tohunga wetewete reo e pā ana ki te kaupapa o tēnei tuhingaroa, arā, te kū o te kupu. Ko ngā tirohanga mō te reo ake, arā, i ahu mai i whea, he aha ōna momo whakaata me tōna pakaritanga ka tirohia i roto i te upoko tuatoru.

Mai i ngā momo whakaata o te reo i roto i ngā momo waiata, ka āta tahuri te kaituhi ki te whakawhānui haere i tana wetewete me tāna tūhononga i ngā rerenga me ngā pekanga o te ku o te kupu.

Kai te upoko tuarima ka tirohia ngā whāinga me ngā aronga ā wētahi kaitito
waiata Māori me wētahi kaikōrero i te reo Māori, mō ō rātau māramatanga ki ngā kū me ngā oro o te reo Māori.

Kai te upoko tuaono e whāriki ana wētahi tauira kōrero Māori, hai whakaata i ngā momo orōmāhara, oro ohorere, ororite, kupu whakahuarua me wērā atu tauira whakaahua i ngā kū o te kupu me ngā oro o te reo Māori.

Ko ngā hua o tēnei rangahau, o tēnei tuhingaroa ka kitea i roto i te upoko
tuawhitu. Kōinei te whakakopinga o tēnei mahi.

text: Te kū o te kupu Ko tēnei tuhingaroa, he rangahau hai wherawhera ake i te āhuatanga o te reo Māori, e kiia ana ko tōna oro, me te kū o ngā kupu kōrero o taua reo. Ko te aronga whakaaro o tēnei rangahau, he rapu i tētahi āhuatanga kāore anō kia tirotirohia, kia tuhia rānei mō te reo Māori. Ehara tēnei rangahau i te kaupapa, i te mahi hou. Otirā, kai te whai te kaituhi i ngā rangahau kua oti kē i wētahi tohunga te wānanga mō wētahi atu reo. Ko tā te kaituhi he whai i ngā tauira a te hunga wetewete reo nei, ka uwhi ai ki runga i te reo Māori hai āwhina i ngā tātaritanga ā te kaituhi mō tōna ake reo, arā, te reo Māori.

Kai te upoko tuatahi ka whaia ngā rerenga whakaaro i pūpū ake ai te taitara 'te kū o te kupu' mō tēnei mahi rangahau. Inā ka tirohia i ahu ngā oro o te reo mai i whea e ai ki tā te Māori wānanga. Mai i ngā oro ka puta ko ngā ku o ngā kupu me ngā kupu o ngā rārangi kōrero.

Hai te upoko tuarua ka tirohia ngā kōrero kua tuhia e ngā tohunga wetewete reo e pā ana ki te kaupapa o tēnei tuhingaroa, arā, te kū o te kupu. Ko ngā tirohanga mō te reo ake, arā, i ahu mai i whea, he aha ōna momo whakaata me tōna pakaritanga ka tirohia i roto i te upoko tuatoru.

Mai i ngā momo whakaata o te reo i roto i ngā momo waiata, ka āta tahuri te kaituhi ki te whakawhānui haere i tana wetewete me tāna tūhononga i ngā rerenga me ngā pekanga o te ku o te kupu.

Kai te upoko tuarima ka tirohia ngā whāinga me ngā aronga ā wētahi kaitito
waiata Māori me wētahi kaikōrero i te reo Māori, mō ō rātau māramatanga ki ngā kū me ngā oro o te reo Māori.

Kai te upoko tuaono e whāriki ana wētahi tauira kōrero Māori, hai whakaata i ngā momo orōmāhara, oro ohorere, ororite, kupu whakahuarua me wērā atu tauira whakaahua i ngā kū o te kupu me ngā oro o te reo Māori.

Ko ngā hua o tēnei rangahau, o tēnei tuhingaroa ka kitea i roto i te upoko
tuawhitu. Kōinei te whakakopinga o tēnei mahi.

year: 2000