title: Mass spectrometry-directed synthesis of  early–late  sulfide-bridged heterobimetallic complexes from the metalloligand [Pt₂(PPh₃)₄(μ-S)₂] and oxo compounds of vanadium(V), molybdenum(VI) and uranium(VI)

authors: Fong, S.W. Audi

subjects: chemistry

abstract: The metalloligand [Pt₂(PPh₃)₄(μ-S)₂] has been found to react with the transition metal oxo compounds, ammonium metavanadate, sodium molybdate, and the actinide complex uranyl nitrate to give sulfide-bridged heterobimetallic complexes [Pt₂(PPh₃)₄(μ₃-S)₂VO(OMe)₂]⁺, [Pt₂(PPh₃)₄(μ₃-S)₂MoO₂(OMe)]⁺, and [Pt₂(PPh₃)₄(μ₃-S)₂UO₂( ₂-NO₃)₂], respectively. Electrospray mass spectrometry (ESMS) was used to probe the reactivity of [Pt₂(PPh₃)₄(μ-S)₂] and thus identify likely targets for isolation and characterization. ESMS has also been used to investigate fragmentation pathways of the new species. No bimetallic species were detected with hydrated La(NO₃)₃or Th(NO₃)₄, or with the lanthanide shift reagent Eu(fod)₃ (fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate). X-Ray crystal structure determinations have been carried out on [Pt₂(PPh₃)₄(μ₃-S)₂VO(OMe)₂]⁺, 2, (as its hexafluorophosphate salt) and [Pt₂(PPh₃)₄(μ₃-S)₂UO₂( ₂-NO₃)₂], 4. The vanadium atom of 2 has a distorted square pyramidal geometry, while the uranium in 4 has the expected linear dioxo coordination geometry, with two bidentate nitrates and a bidentate {Pt₂S₂} moiety.

text: Mass spectrometry-directed synthesis of  early–late  sulfide-bridged heterobimetallic complexes from the metalloligand [Pt₂(PPh₃)₄(μ-S)₂] and oxo compounds of vanadium(V), molybdenum(VI) and uranium(VI) The metalloligand [Pt₂(PPh₃)₄(μ-S)₂] has been found to react with the transition metal oxo compounds, ammonium metavanadate, sodium molybdate, and the actinide complex uranyl nitrate to give sulfide-bridged heterobimetallic complexes [Pt₂(PPh₃)₄(μ₃-S)₂VO(OMe)₂]⁺, [Pt₂(PPh₃)₄(μ₃-S)₂MoO₂(OMe)]⁺, and [Pt₂(PPh₃)₄(μ₃-S)₂UO₂( ₂-NO₃)₂], respectively. Electrospray mass spectrometry (ESMS) was used to probe the reactivity of [Pt₂(PPh₃)₄(μ-S)₂] and thus identify likely targets for isolation and characterization. ESMS has also been used to investigate fragmentation pathways of the new species. No bimetallic species were detected with hydrated La(NO₃)₃or Th(NO₃)₄, or with the lanthanide shift reagent Eu(fod)₃ (fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate). X-Ray crystal structure determinations have been carried out on [Pt₂(PPh₃)₄(μ₃-S)₂VO(OMe)₂]⁺, 2, (as its hexafluorophosphate salt) and [Pt₂(PPh₃)₄(μ₃-S)₂UO₂( ₂-NO₃)₂], 4. The vanadium atom of 2 has a distorted square pyramidal geometry, while the uranium in 4 has the expected linear dioxo coordination geometry, with two bidentate nitrates and a bidentate {Pt₂S₂} moiety.

year: 2002

title: Supporting Organisational Critical Activities From Web Sites: An Evaluation Methodology Development

authors: Hung, Wei-Hsi (Frank)

subjects: Organisational critical activities

abstract: quot; Organisational critical activities quot; (OCAs) are activities which must be conducted by the organisation constantly in order to be successful in the industry. They are recognised as being essential to short, medium, and long-term success in that industry, have been significantly resourced and receive regular senior management monitoring and direction. Although these activities are extremely important, some empirical studies have shown that they are not well supported by organisations, particularly in the area of Web support. This thesis develops an evaluation methodology called the quot;organisational critical activity Web support evaluation methodology quot; (OCAWSEM) which can be utilised to elicit OCAs from organisations, evaluate whether an organisation acutes; OCAs are being supported by its Web site, and provide guidance on how the organisation can improve its Web site. To develop the OCAWSEM, this thesis reviews the relevant literature and proposes a prototype OCAWSEM. A new iterative case design (ICD) approach has been used in order to further develop the prototype, and then to test the improved OCAWSEM. The selected field cases were eight universities in New Zealand. In total, 43 semi-structured interviews were conducted with senior teams, middle level managers, and Web teams. A systematic review of these universitiesacute Web sites was performed from the provideracutes, rather than the useracutes perspective. The outcome shows that the Developed OCAWSEM is a valid and reliable methodology for the evaluation of the support for OCAs from Web sites in the universities in New Zealand. This thesis provides useful lessons, drawn from the development and testing processes, as the basis from which to develop more specific OCAWSEMs for use in other organisational and industry contexts. Both practitioners and academicians can gain a deeper understanding of the notion of OCAs, better elicit OCAs from management, conduct Web site evaluations, and discuss the support of the Web sites for the OCAs.

text: Supporting Organisational Critical Activities From Web Sites: An Evaluation Methodology Development quot; Organisational critical activities quot; (OCAs) are activities which must be conducted by the organisation constantly in order to be successful in the industry. They are recognised as being essential to short, medium, and long-term success in that industry, have been significantly resourced and receive regular senior management monitoring and direction. Although these activities are extremely important, some empirical studies have shown that they are not well supported by organisations, particularly in the area of Web support. This thesis develops an evaluation methodology called the quot;organisational critical activity Web support evaluation methodology quot; (OCAWSEM) which can be utilised to elicit OCAs from organisations, evaluate whether an organisation acutes; OCAs are being supported by its Web site, and provide guidance on how the organisation can improve its Web site. To develop the OCAWSEM, this thesis reviews the relevant literature and proposes a prototype OCAWSEM. A new iterative case design (ICD) approach has been used in order to further develop the prototype, and then to test the improved OCAWSEM. The selected field cases were eight universities in New Zealand. In total, 43 semi-structured interviews were conducted with senior teams, middle level managers, and Web teams. A systematic review of these universitiesacute Web sites was performed from the provideracutes, rather than the useracutes perspective. The outcome shows that the Developed OCAWSEM is a valid and reliable methodology for the evaluation of the support for OCAs from Web sites in the universities in New Zealand. This thesis provides useful lessons, drawn from the development and testing processes, as the basis from which to develop more specific OCAWSEMs for use in other organisational and industry contexts. Both practitioners and academicians can gain a deeper understanding of the notion of OCAs, better elicit OCAs from management, conduct Web site evaluations, and discuss the support of the Web sites for the OCAs.

year: 2006

title: Telomere length in early childhood is associated with sex and ethnicity

authors: Ly, Kien

subjects: Science & Technology

abstract: Telomeres are repetitive DNA sequences at the end of chromosomes that function to protect chromosomes from degradation. Throughout the life course, telomere length decreases with age and is influenced by environmental factors and health conditions. This study aimed to determine the relative telomere lengths in a diverse cohort of about 4000 four-year-old children in New Zealand. Linear regression was used to investigate the relationship between telomere length, child gender, ethnicity, paternal age and deprivation. We observed substantial variation in telomere length according to sex and self-identified ethnicity. Telomere length was longer in females compared to males (coefficient of 0.042, 95% confidence interval (CI) 0.024–0.060). European children had shorter telomere than both the indigenous Māori (coefficient of 0.03, CI 0.007–0.055) and Pacific children (coefficient of 0.15, CI 0.12–0.18). The data suggest that telomere lengths are highly variable and variability between individuals arise from early age, influenced partly by sex and ethnicity. Longer telomeres in indigenous Māori and Pacific children may reflect the heritability of telomere length in genetically less complex populations. This study increases our understanding of telomere dynamics in young children since the majority of telomere studies are conducted in adults.

text: Telomere length in early childhood is associated with sex and ethnicity Telomeres are repetitive DNA sequences at the end of chromosomes that function to protect chromosomes from degradation. Throughout the life course, telomere length decreases with age and is influenced by environmental factors and health conditions. This study aimed to determine the relative telomere lengths in a diverse cohort of about 4000 four-year-old children in New Zealand. Linear regression was used to investigate the relationship between telomere length, child gender, ethnicity, paternal age and deprivation. We observed substantial variation in telomere length according to sex and self-identified ethnicity. Telomere length was longer in females compared to males (coefficient of 0.042, 95% confidence interval (CI) 0.024–0.060). European children had shorter telomere than both the indigenous Māori (coefficient of 0.03, CI 0.007–0.055) and Pacific children (coefficient of 0.15, CI 0.12–0.18). The data suggest that telomere lengths are highly variable and variability between individuals arise from early age, influenced partly by sex and ethnicity. Longer telomeres in indigenous Māori and Pacific children may reflect the heritability of telomere length in genetically less complex populations. This study increases our understanding of telomere dynamics in young children since the majority of telomere studies are conducted in adults.

year: 2019