title: High-resolution radiocarbon dating of marine materials in archaeological contexts: radiocarbon marine reservoir variability between Anadara, Gafrarium, Batissa, Polymesoda spp. and Echinoidea at Caution Bay, Southern Coastal Papua New Guinea

authors: Petchey, Fiona

subjects: radiocarbon

abstract: The remains of shellfish dominate many coastal archaeological sites in the Pacific and provide a wealth of information about economy, culture, environment and climate. Shells are therefore the logical sample type to develop local and regional radiocarbon chronologies. The calibration of radiocarbon (¹⁴C) dates on marine animals is not straightforward, however, requiring an understanding of habitat and dietary preferences as well as detailed knowledge of local ocean conditions. The most complex situations occur where terrestrial influences impinge on the marine environment resulting in both the enrichment and depletion of ¹⁴C (Ulm Geoarchaeology 17(4):319–348, 2002; Petchey and Clark Quat Geochronol 6:539–549, 2011). A sampling protocol that combines a high-resolution excavation methodology, selection of short-lived samples identified to species level, and a tri-isotope approach using ¹⁴C, δ¹³C and δ¹⁸O, has given us the ability to identify ¹⁴C source variation that would otherwise have been obscured. Here, we present new research that details high-resolution mapping of marine 14C reservoir variation between Gafrarium tumidum, Gafrarium pectinatum, Anadara granosa, Anadara antiquata, Batissa violacea, Polymesoda erosa and Echinoidea from the Bogi 1 archaeological site, Caution Bay, southern coastal Papua New Guinea. These isotopes highlight specific dietary, habitat and behavioural variations that are key to obtaining chronological information from shell radiocarbon determinations.

text: High-resolution radiocarbon dating of marine materials in archaeological contexts: radiocarbon marine reservoir variability between Anadara, Gafrarium, Batissa, Polymesoda spp. and Echinoidea at Caution Bay, Southern Coastal Papua New Guinea The remains of shellfish dominate many coastal archaeological sites in the Pacific and provide a wealth of information about economy, culture, environment and climate. Shells are therefore the logical sample type to develop local and regional radiocarbon chronologies. The calibration of radiocarbon (¹⁴C) dates on marine animals is not straightforward, however, requiring an understanding of habitat and dietary preferences as well as detailed knowledge of local ocean conditions. The most complex situations occur where terrestrial influences impinge on the marine environment resulting in both the enrichment and depletion of ¹⁴C (Ulm Geoarchaeology 17(4):319–348, 2002; Petchey and Clark Quat Geochronol 6:539–549, 2011). A sampling protocol that combines a high-resolution excavation methodology, selection of short-lived samples identified to species level, and a tri-isotope approach using ¹⁴C, δ¹³C and δ¹⁸O, has given us the ability to identify ¹⁴C source variation that would otherwise have been obscured. Here, we present new research that details high-resolution mapping of marine 14C reservoir variation between Gafrarium tumidum, Gafrarium pectinatum, Anadara granosa, Anadara antiquata, Batissa violacea, Polymesoda erosa and Echinoidea from the Bogi 1 archaeological site, Caution Bay, southern coastal Papua New Guinea. These isotopes highlight specific dietary, habitat and behavioural variations that are key to obtaining chronological information from shell radiocarbon determinations.

year: 2013

title: The Role of Differential outcomes on Gambling Behaviour

authors: Staples, Krystal Nell

subjects: Gambling

abstract: This research is based on the conduction of a series of experiments that systematically occurred based on participants performance on a gambling simulation. In Experiment 1, a Roulette simulation allowed the manipulation of the probability that a win would occur after a bet on red or black. First year psychology students (N=18) participated for extra course credit and were randomly assigned to one of three experimental conditions (Group 1a started with $100 credit, experienced 70% probability of a win on red and 10% probability of a win on black with red and black results being drawn evenly; Group 2a experienced the same conditions as Group 1a except for a higher starting credit of $500; Group 1c started with $500 credit, experienced 100% probability of a win on red and a 0% probability of a win on black with red and black numbers being drawn equally). Results showed that the majority of participants did not match betting behaviour to reinforcement outcomes. In Experiment 2 the simulation was simplified. Group 2a experienced 70% probability of a win on red and 10% probability of a win on black with both red and black numbers being drawn equally; Group 2b experienced 100% probability of a win on red and 0% probability on black with 90% of numbers drawn by the computer being red and 10% black; Group 2c had 75% probability of winning on red and 25% probability of a win on black with 75% of results drawn being red and 25% being black. Results show that participants gambling behaviour was roughly proportional to the amount of reinforcement received on each colour, demonstrating reinforcer control over participant‟s behaviour, so called matching. These differing results are then discussed in relation to the possible implications for future research.

text: The Role of Differential outcomes on Gambling Behaviour This research is based on the conduction of a series of experiments that systematically occurred based on participants performance on a gambling simulation. In Experiment 1, a Roulette simulation allowed the manipulation of the probability that a win would occur after a bet on red or black. First year psychology students (N=18) participated for extra course credit and were randomly assigned to one of three experimental conditions (Group 1a started with $100 credit, experienced 70% probability of a win on red and 10% probability of a win on black with red and black results being drawn evenly; Group 2a experienced the same conditions as Group 1a except for a higher starting credit of $500; Group 1c started with $500 credit, experienced 100% probability of a win on red and a 0% probability of a win on black with red and black numbers being drawn equally). Results showed that the majority of participants did not match betting behaviour to reinforcement outcomes. In Experiment 2 the simulation was simplified. Group 2a experienced 70% probability of a win on red and 10% probability of a win on black with both red and black numbers being drawn equally; Group 2b experienced 100% probability of a win on red and 0% probability on black with 90% of numbers drawn by the computer being red and 10% black; Group 2c had 75% probability of winning on red and 25% probability of a win on black with 75% of results drawn being red and 25% being black. Results show that participants gambling behaviour was roughly proportional to the amount of reinforcement received on each colour, demonstrating reinforcer control over participant‟s behaviour, so called matching. These differing results are then discussed in relation to the possible implications for future research.

year: 2012

title: Estimated catchment loads of nitrogen and phosphorus to the Rotorua Te Arawa Lakes

authors: McBride, Chris G.

abstract: The Rotorua Te Arawa Lakes are central to the identity of their region, of immense historical and cultural importance, and provide ecosystem services that underpin biodiversity, conservation and socioeconomic aspirations of the community. The diversity of water quality in the lakes reflects their catchments, which are diverse in topography, hydrogeology and intensity of land use, ranging from the largely undeveloped land around lakes Tikitapu and Okataina, to highly developed forestry and pastoral land around lakes Rerewhakaaitu, Rotorua and Okaro. Lake water quality is strongly linked to nutrients received by each lake from surface flows and groundwater springs. It therefore follows that management of lake water quality requires a good understanding of nutrient loads derived from the landscape, as does the assessment or prediction of the in-lake effects of catchment-based management initiatives aimed at improving lake water quality.

text: Estimated catchment loads of nitrogen and phosphorus to the Rotorua Te Arawa Lakes The Rotorua Te Arawa Lakes are central to the identity of their region, of immense historical and cultural importance, and provide ecosystem services that underpin biodiversity, conservation and socioeconomic aspirations of the community. The diversity of water quality in the lakes reflects their catchments, which are diverse in topography, hydrogeology and intensity of land use, ranging from the largely undeveloped land around lakes Tikitapu and Okataina, to highly developed forestry and pastoral land around lakes Rerewhakaaitu, Rotorua and Okaro. Lake water quality is strongly linked to nutrients received by each lake from surface flows and groundwater springs. It therefore follows that management of lake water quality requires a good understanding of nutrient loads derived from the landscape, as does the assessment or prediction of the in-lake effects of catchment-based management initiatives aimed at improving lake water quality.

year: 2021