title: Testing for bubbles in time series data using long historical series

authors: Hu, Yang

subjects: thesis with publication

abstract: The concept of asset price bubble has drawn a large amount of academic attention. A bubble is commonly defined as where the asset price is not justified by expectations of the fundamentals. The empirical characteristics of a bubble are widely regarded as a dramatic rise in asset prices in the early periods along with a sudden collapse, which have been observed in a wide range of financial markets including commodity, real estate and stock.
This thesis attempts to examine several well-noticed bubble episodes in history, for example, the Mississippi Bubble in 1719, the South Sea Bubble in 1719-20, Japan’s asset price bubble during the 1980s and the more recent US real estate bubble in the early 2000s. One of the greatest contribution of this thesis is that it has provided econometric-based evidence to support the existence of these famous episodes for the first time using recently developed econometric tests. The origination and collapse dates for these identified episodes are coincided with the traditional view of famous bubbles.
This thesis not only tests for the existence of bubbles but also seeks to provide some empirical evidence to support the existence of bubble spillovers/contagion using the most-documented bubble episodes. The first example considered in this thesis is whether financial bubbles/crises spill-over to housing markets in Amsterdam, Norway and France. The second example is considered for a number of British financial organisations during the South Sea episode in 1719-20 (e.g., the South Sea Company, the Bank of England, East India Company, London Assurance, Million Bank, the Royal African Company and the Royal Exchange Assurance). The South Sea Bubble seems to migrate to other organisations as the British share market was speculative for that period. The timings of some identified episodes can be viewed as possible evidence of spillovers or contagion for this important period in England. The third example looks at the Japan’s real estate and stock markets during the 1980-90s. Based on econometric tools, the findings indicate signs of bubble migration from Japan’s stock market to its real estate market for the first time. Even if this phenomenon has been observed in the literature, none of existing studies provide any solid evidences to support this claim.
This thesis investigates the long-run equilibrium relationship between house prices and economic fundamentals in the US based on quantile cointegration approaches for the first time. The presence of cointegration between house prices and fundamentals would imply convergence to a stable equilibrium relationship, suggesting a temporary run-up or drop in house prices would eventually come back to the equilibrium. By making use of quantile autoregressive distributed lag model (QARDL), this research explores the cointegration relationship across the whole
conditional distribution.

text: Testing for bubbles in time series data using long historical series The concept of asset price bubble has drawn a large amount of academic attention. A bubble is commonly defined as where the asset price is not justified by expectations of the fundamentals. The empirical characteristics of a bubble are widely regarded as a dramatic rise in asset prices in the early periods along with a sudden collapse, which have been observed in a wide range of financial markets including commodity, real estate and stock.
This thesis attempts to examine several well-noticed bubble episodes in history, for example, the Mississippi Bubble in 1719, the South Sea Bubble in 1719-20, Japan’s asset price bubble during the 1980s and the more recent US real estate bubble in the early 2000s. One of the greatest contribution of this thesis is that it has provided econometric-based evidence to support the existence of these famous episodes for the first time using recently developed econometric tests. The origination and collapse dates for these identified episodes are coincided with the traditional view of famous bubbles.
This thesis not only tests for the existence of bubbles but also seeks to provide some empirical evidence to support the existence of bubble spillovers/contagion using the most-documented bubble episodes. The first example considered in this thesis is whether financial bubbles/crises spill-over to housing markets in Amsterdam, Norway and France. The second example is considered for a number of British financial organisations during the South Sea episode in 1719-20 (e.g., the South Sea Company, the Bank of England, East India Company, London Assurance, Million Bank, the Royal African Company and the Royal Exchange Assurance). The South Sea Bubble seems to migrate to other organisations as the British share market was speculative for that period. The timings of some identified episodes can be viewed as possible evidence of spillovers or contagion for this important period in England. The third example looks at the Japan’s real estate and stock markets during the 1980-90s. Based on econometric tools, the findings indicate signs of bubble migration from Japan’s stock market to its real estate market for the first time. Even if this phenomenon has been observed in the literature, none of existing studies provide any solid evidences to support this claim.
This thesis investigates the long-run equilibrium relationship between house prices and economic fundamentals in the US based on quantile cointegration approaches for the first time. The presence of cointegration between house prices and fundamentals would imply convergence to a stable equilibrium relationship, suggesting a temporary run-up or drop in house prices would eventually come back to the equilibrium. By making use of quantile autoregressive distributed lag model (QARDL), this research explores the cointegration relationship across the whole
conditional distribution.

year: 2019

title: Identifying iron-binding antioxidants in New Zealand honeydew honey

authors: Omar, Syaliza Binti

subjects: antioxidants

abstract: Iron is an essential element for human physiological function. However, excess free iron could participate in the formation of reactive oxygen species via the Fenton reaction and is thought to be the primary mechanism for the pathogenesis of diseases related to iron excess. Prevention of the oxidative damage caused by reactive oxygen species can be accomplished by using selective iron-binding compounds. Beech honeydew honey has been found to have an exceptionally high level of iron-binding antioxidant activity. Due to that, the focus of the research in this thesis has been to isolate the compound(s) responsible for the activity and identify their molecular structure.
The stability of the antioxidants on exposure to heat and high and low pH was investigated to get a better understanding of the conditions which could be used when developing suitable techniques for the isolation of the iron-binding antioxidants. 
The isolation of the antioxidants was first attempted with XAD-2 resin. The results of solid phase extraction using XAD-2 resin showed that the activity is mainly found in the honey effluent, the fraction not retarded by the resin, indicating that hydrophilic components contributed to the iron-binding antioxidant activity. The phenolic compounds isolated from this resin did not exhibit iron-binding antioxidant activity.
When the antioxidants could not be isolated from the XAD-2 resin, size exclusion chromatography was used to separate the honey components based on their molecular sizes. The technique was successsful in separating antioxidants from free sugars in honey. However, size exclusion chromatography did not give any significant information regarding the identity of the antioxidants. Thus, two types of chromatography (reversed phase and anion exchange) were used in sequence to aid the separation of components of the active fraction from size exclusion chromatography. This procedure however was not compatible with subsequent mass spectrometry since a high level of sodium chloride existed in the final fraction, even after desalting using reversed phase column chromatography. Due to that, other means of chromatography were trialled in order to obtain a salt-free fraction prior to mass spectrometry. The first procedure was modified by switching the sequence of the columns used, and different mobile phases without salt were used. This second procedure was successful in isolating the antioxidants and the compounds have been characterised by mass spectrometry.
Mass spectrometry revealed that the antioxidants isolated were compounds of low molecular weight (i.e. 255, 283 and 227) which exhibited peaks with high intensity. Nuclear magnetic resonance (NMR) spectroscopy of the active fraction showed that the antioxidant may possess a 1,4-disubstituted aromatic ring. However, full elucidation of the structure of the compound was not possible because of the very low mass of the material that had been isolated. 
Other than the information gained from mass spectrometry and NMR, the antioxidant also could be characterised by forming the negative ion at pH 9.5–10. The UV absorbance at 220 and 280 nm, but not at 360 nm is indicative that the antioxidant possess a phenolic ring but not a flavonoid in the molecular structure.
Complete structural elucidation of the iron-binding antioxidants in honeydew honey could initiate a better understanding of the mechanism of action of the antioxidants. This could increase the use of honeydew honey in pharmaceutical and nutraceutical products as an iron-binding antioxidant. There is also the possibility that the identified compound(s) could be synthesised for pharmaceutical use, or serve as lead compounds for the development of other pharmaceutical iron-binding antioxidants.

text: Identifying iron-binding antioxidants in New Zealand honeydew honey Iron is an essential element for human physiological function. However, excess free iron could participate in the formation of reactive oxygen species via the Fenton reaction and is thought to be the primary mechanism for the pathogenesis of diseases related to iron excess. Prevention of the oxidative damage caused by reactive oxygen species can be accomplished by using selective iron-binding compounds. Beech honeydew honey has been found to have an exceptionally high level of iron-binding antioxidant activity. Due to that, the focus of the research in this thesis has been to isolate the compound(s) responsible for the activity and identify their molecular structure.
The stability of the antioxidants on exposure to heat and high and low pH was investigated to get a better understanding of the conditions which could be used when developing suitable techniques for the isolation of the iron-binding antioxidants. 
The isolation of the antioxidants was first attempted with XAD-2 resin. The results of solid phase extraction using XAD-2 resin showed that the activity is mainly found in the honey effluent, the fraction not retarded by the resin, indicating that hydrophilic components contributed to the iron-binding antioxidant activity. The phenolic compounds isolated from this resin did not exhibit iron-binding antioxidant activity.
When the antioxidants could not be isolated from the XAD-2 resin, size exclusion chromatography was used to separate the honey components based on their molecular sizes. The technique was successsful in separating antioxidants from free sugars in honey. However, size exclusion chromatography did not give any significant information regarding the identity of the antioxidants. Thus, two types of chromatography (reversed phase and anion exchange) were used in sequence to aid the separation of components of the active fraction from size exclusion chromatography. This procedure however was not compatible with subsequent mass spectrometry since a high level of sodium chloride existed in the final fraction, even after desalting using reversed phase column chromatography. Due to that, other means of chromatography were trialled in order to obtain a salt-free fraction prior to mass spectrometry. The first procedure was modified by switching the sequence of the columns used, and different mobile phases without salt were used. This second procedure was successful in isolating the antioxidants and the compounds have been characterised by mass spectrometry.
Mass spectrometry revealed that the antioxidants isolated were compounds of low molecular weight (i.e. 255, 283 and 227) which exhibited peaks with high intensity. Nuclear magnetic resonance (NMR) spectroscopy of the active fraction showed that the antioxidant may possess a 1,4-disubstituted aromatic ring. However, full elucidation of the structure of the compound was not possible because of the very low mass of the material that had been isolated. 
Other than the information gained from mass spectrometry and NMR, the antioxidant also could be characterised by forming the negative ion at pH 9.5–10. The UV absorbance at 220 and 280 nm, but not at 360 nm is indicative that the antioxidant possess a phenolic ring but not a flavonoid in the molecular structure.
Complete structural elucidation of the iron-binding antioxidants in honeydew honey could initiate a better understanding of the mechanism of action of the antioxidants. This could increase the use of honeydew honey in pharmaceutical and nutraceutical products as an iron-binding antioxidant. There is also the possibility that the identified compound(s) could be synthesised for pharmaceutical use, or serve as lead compounds for the development of other pharmaceutical iron-binding antioxidants.

year: 2013

title: Tūturu whakamaua ko te kupu, haumi e, hui e, ko ngā kupu o te mātauranga ē!

authors: Dale, Hēmi

subjects: Reo Māori

abstract: Ko tā tēnei tuhinga he arotahi ki ētahi o ngā take reo e pā ana ki ngā mahi whakangungu pouako mā te huarahi o te reo Māori i roto i te whare wānanga. Ka mutu, ka kōrerorerotia ngā urupare a te Huarahi Māori (tētahi kaiwhakarato whakangungu pouako mā te huarahi o te reo Māori) ki ētahi o ēnei take reo.

text: Tūturu whakamaua ko te kupu, haumi e, hui e, ko ngā kupu o te mātauranga ē! Ko tā tēnei tuhinga he arotahi ki ētahi o ngā take reo e pā ana ki ngā mahi whakangungu pouako mā te huarahi o te reo Māori i roto i te whare wānanga. Ka mutu, ka kōrerorerotia ngā urupare a te Huarahi Māori (tētahi kaiwhakarato whakangungu pouako mā te huarahi o te reo Māori) ki ētahi o ēnei take reo.

year: 2017