title: Identifying temporal and spatial variations in the binding properties of transition metal-organic ligand complexes in cave waters using organic inclusions in speleothem calcite: Implications for paleoclimate research.

authors: Brodnax, Robert

subjects: speleothems

abstract: Speleothems such as stalagmites, stalactites and flowstones, contain paleoclimate information encoded in their geochemical properties. One of these properties, transition metal abundance in speleothem calcite, is tightly controlled by complexation reactions in cave water with dissolved organic matter (DOM). Organic compounds are also preserved in speleothem deposits. DOM structure varies from cave system to cave system and over time, but whether these structural variations meaningfully alter the way DOM controls trace metal incorporation into calcite is unclear. This is relevant to the development of speleothem transition metal content as a paleoclimate proxy, particularly over large spatial and temporal scales where DOM structure variations are likely. This study identifies variations in the binding properties of DOM preserved in speleothem calcite over time and space by extracting organic compounds of known age and origin from speleothems collected from New Zealand, Niuean, British, and Australian cave systems. The kinetic properties of DOM complexes from these extracts were measured using small volume diffusive gradients in thin films (SV-DGT) and the variation in the binding strength of complexes with Cu, Co, and Ni was compared across time and space. DOM binding of Cu and Co were found to vary significantly depending on the cave system from which the DOM originated. Whether this variation was linked to climate changes represented in the age of the DOM or to changes in system characteristics related to geographical setting was unclear. Despite this, it is apparent that there are factors related to the origin of DOM in cave systems that influence the kinetic restrictions applied to transition metals in cave water. This variability should be considered when linking trace element contents in cave precipitates to paleoclimate change.

text: Identifying temporal and spatial variations in the binding properties of transition metal-organic ligand complexes in cave waters using organic inclusions in speleothem calcite: Implications for paleoclimate research. Speleothems such as stalagmites, stalactites and flowstones, contain paleoclimate information encoded in their geochemical properties. One of these properties, transition metal abundance in speleothem calcite, is tightly controlled by complexation reactions in cave water with dissolved organic matter (DOM). Organic compounds are also preserved in speleothem deposits. DOM structure varies from cave system to cave system and over time, but whether these structural variations meaningfully alter the way DOM controls trace metal incorporation into calcite is unclear. This is relevant to the development of speleothem transition metal content as a paleoclimate proxy, particularly over large spatial and temporal scales where DOM structure variations are likely. This study identifies variations in the binding properties of DOM preserved in speleothem calcite over time and space by extracting organic compounds of known age and origin from speleothems collected from New Zealand, Niuean, British, and Australian cave systems. The kinetic properties of DOM complexes from these extracts were measured using small volume diffusive gradients in thin films (SV-DGT) and the variation in the binding strength of complexes with Cu, Co, and Ni was compared across time and space. DOM binding of Cu and Co were found to vary significantly depending on the cave system from which the DOM originated. Whether this variation was linked to climate changes represented in the age of the DOM or to changes in system characteristics related to geographical setting was unclear. Despite this, it is apparent that there are factors related to the origin of DOM in cave systems that influence the kinetic restrictions applied to transition metals in cave water. This variability should be considered when linking trace element contents in cave precipitates to paleoclimate change.

year: 2024

title: A note on the average propensity to consume, wealth and threshold adjustment

authors: Holmes, Mark J.

subjects: threshold error correction

abstract: We explore the connection between the average propensity to consume (APC) and wealth to income ratio (WY) in the US. We find evidence of a long-run relationship characterised by threshold error correction. It is the APC that responds to long-run disequilibrium where the speed of adjustment is asymmetric insofar as being most likely fastest in regimes characterised by a high APC and low WY.

text: A note on the average propensity to consume, wealth and threshold adjustment We explore the connection between the average propensity to consume (APC) and wealth to income ratio (WY) in the US. We find evidence of a long-run relationship characterised by threshold error correction. It is the APC that responds to long-run disequilibrium where the speed of adjustment is asymmetric insofar as being most likely fastest in regimes characterised by a high APC and low WY.

year: 2013

title: Identifying fisheries regions in New Zealand: Some conceptual difficulties

authors: Rennie, Hamish Gordon

subjects: Fisheries

abstract: The importance of fisheries to nations is reflected in the production and employment statistics of the country. It is also reflected in socio-cultural symbols (for instance songs, tales), and in socio-political hegemonies.  Just as these may vary from one nation to another, they may also vary from region to region within a nation.  Several nations speak openly in terms of 'fisheries regions' and there have been a number of attempts to identify such regions in the social science literature. An understanding of these regions is seen as step towards defining appropriate policies for the sustainable management of their resources.

In 1986, New Zealand established an innovative fishery management system based on individually transferable quota (ITQ), and subsequently removed the (never-implemented) region-based, fishery management planning structure from the statutes.  These changes might be indicative of a loss of geography, a flattening of the nation's "fishing topography", and might be expected to result in significant changes to the nature and location of fisheries regions.

This paper outlines the changes in the management structure of New Zealand's fisheries. We then attempt a preliminary analysis of fisheries regions in New Zealand as the basis for a "new regional" geography of New Zealand's fisheries. In the process we discuss various criteria for defining fishery regions and present our initial categorisation of New Zealand into those regions. The relationship between these regions and related institutional structures is then discussed. This raises a number of additional questions regarding the concept of a fisheries region, especially in the context of a resurgent indigenous (Maaori) culture, the emergence of new fishing peoples in New Zealand, and the respective size of recreational and commercial fishing sectors.

text: Identifying fisheries regions in New Zealand: Some conceptual difficulties The importance of fisheries to nations is reflected in the production and employment statistics of the country. It is also reflected in socio-cultural symbols (for instance songs, tales), and in socio-political hegemonies.  Just as these may vary from one nation to another, they may also vary from region to region within a nation.  Several nations speak openly in terms of 'fisheries regions' and there have been a number of attempts to identify such regions in the social science literature. An understanding of these regions is seen as step towards defining appropriate policies for the sustainable management of their resources.

In 1986, New Zealand established an innovative fishery management system based on individually transferable quota (ITQ), and subsequently removed the (never-implemented) region-based, fishery management planning structure from the statutes.  These changes might be indicative of a loss of geography, a flattening of the nation's "fishing topography", and might be expected to result in significant changes to the nature and location of fisheries regions.

This paper outlines the changes in the management structure of New Zealand's fisheries. We then attempt a preliminary analysis of fisheries regions in New Zealand as the basis for a "new regional" geography of New Zealand's fisheries. In the process we discuss various criteria for defining fishery regions and present our initial categorisation of New Zealand into those regions. The relationship between these regions and related institutional structures is then discussed. This raises a number of additional questions regarding the concept of a fisheries region, especially in the context of a resurgent indigenous (Maaori) culture, the emergence of new fishing peoples in New Zealand, and the respective size of recreational and commercial fishing sectors.

year: 1998-06-01