title: Exploring the Lewis basicity of the metalloligand [Pt₂(μ-Se)₂(PPh₃)₄] on metal substrates by electrospray mass spectrometry. Synthesis, characterization and structural studies of new platinum selenido phosphine complexes containing the {Pt₂Se₂} core

authors: Yeo, Jeremy S.L.

subjects: chemistry

abstract: Electrospray Mass Spectrometry (ESMS) has been used as a tool to probe the reactivity of the metalloligand [Pt₂(μ-Se)₂(PPh₃)₄] with metal substrates, which lead to the formation of charged coordination complexes via loss of halides or other labile ligands. Among the numerous metal substrates used in the displacement reactions are Au(anpy)Cl₂ (anpy = cyclometallated 2-anilinopyridyl), HgPhCl and Pb(NO₃)₂. Acid titration on the Lewis basic metalloligand leads to the identification and isolation of the doubly-protonated species, [Pt₂(μ-SeH)₂(PPh₃)₄]²⁺, whose sulfide analogue cannot be isolated. A three-step strategy is employed in the use of ESMS as a probe: (i) preliminary screening of the metalloligand with an array of acidic main group and transition group metal compounds, (ii) identification of potentially stable and isolable products formed in situ based on ion distribution and simulated isotope patterns and (iii) promising reactions are repeated on a laboratory scale, and target products are isolated and characterized. X-Ray diffraction studies have been performed on single crystals of [Pt₂(μ-SeH)₂(PPh₃)₄][ClO₄]₂, [Pt₂(μ₃-Se)₂(PPh₃)₄(CdCl₂)] and {Pt₂(μ₃-Se)₂(PPh₃)₄[Pb(NO₃)]}{NO₃}. These results suggested that in general a parallel chemistry can be developed on the intermetallic selenides as on the sulfides. However, there are chemical and structural differences which are highlighted in this paper.

text: Exploring the Lewis basicity of the metalloligand [Pt₂(μ-Se)₂(PPh₃)₄] on metal substrates by electrospray mass spectrometry. Synthesis, characterization and structural studies of new platinum selenido phosphine complexes containing the {Pt₂Se₂} core Electrospray Mass Spectrometry (ESMS) has been used as a tool to probe the reactivity of the metalloligand [Pt₂(μ-Se)₂(PPh₃)₄] with metal substrates, which lead to the formation of charged coordination complexes via loss of halides or other labile ligands. Among the numerous metal substrates used in the displacement reactions are Au(anpy)Cl₂ (anpy = cyclometallated 2-anilinopyridyl), HgPhCl and Pb(NO₃)₂. Acid titration on the Lewis basic metalloligand leads to the identification and isolation of the doubly-protonated species, [Pt₂(μ-SeH)₂(PPh₃)₄]²⁺, whose sulfide analogue cannot be isolated. A three-step strategy is employed in the use of ESMS as a probe: (i) preliminary screening of the metalloligand with an array of acidic main group and transition group metal compounds, (ii) identification of potentially stable and isolable products formed in situ based on ion distribution and simulated isotope patterns and (iii) promising reactions are repeated on a laboratory scale, and target products are isolated and characterized. X-Ray diffraction studies have been performed on single crystals of [Pt₂(μ-SeH)₂(PPh₃)₄][ClO₄]₂, [Pt₂(μ₃-Se)₂(PPh₃)₄(CdCl₂)] and {Pt₂(μ₃-Se)₂(PPh₃)₄[Pb(NO₃)]}{NO₃}. These results suggested that in general a parallel chemistry can be developed on the intermetallic selenides as on the sulfides. However, there are chemical and structural differences which are highlighted in this paper.

year: 2002

title: Measures of Rowing Performance

authors: Smith, Tiaki Brett

subjects: performance measures

abstract: Accurate measures of performance are important for assessing competitive athletes in practical and research settings. We present here a review of rowing performance measures, focusing on the errors in these measures and the implications for testing rowers. The yardstick for assessing error in a performance measure is the random variation (typical or standard error of measurement) in an elite athlete's competitive performance from race to race: ∼1.0% for time in 2000 m rowing events. There has been little research interest in on-water time trials for assessing rowing performance, owing to logistic difficulties and environmental perturbations in performance time with such tests. Mobile ergometry via instrumented oars or rowlocks should reduce these problems, but the associated errors have not yet been reported. Measurement of boat speed to monitor on-water training performance is common; one device based on global positioning system (GPS) technology contributes negligible extra random error (0.2%) in speed measured over 2000 m, but extra error is substantial (1-10%) with other GPS devices or with an impeller, especially over shorter distances. The problems with on-water testing have led to widespread use of the Concept II rowing ergometer. The standard error of the estimate of on-water 2000 m time predicted by 2000 m ergometer performance was 2.6% and 7.2% in two studies, reflecting different effects of skill, body mass and environment in on-water versus ergometer performance. However, well trained rowers have a typical error in performance time of only ∼0.5% between repeated 2000 m time trials on this ergometer, so such trials are suitable for tracking changes in physiological performance and factors affecting it. Many researchers have used the 2000 m ergometer performance time as a criterion to identify other predictors of rowing performance. Standard errors of the estimate vary widely between studies even for the same predictor, but the lowest errors (~1-2%) have been observed for peak power output in an incremental test, some measures of lactate threshold and measures of 30-second all-out power. Some of these measures also have typical error between repeated tests suitably low for tracking changes. Combining measures via multiple linear regression needs further investigation. In summary, measurement of boat speed, especially with a good GPS device, has adequate precision for monitoring training performance, but adjustment for environmental effects needs to be investigated. Time trials on the Concept II ergometer provide accurate estimates of a rower's physiological ability to output power, and some submaximal and brief maximal ergometer performance measures can be used frequently to monitor changes in this ability. On-water performance measured via instrumented skiffs that determine individual power output may eventually surpass measures derived from the Concept II.

text: Measures of Rowing Performance Accurate measures of performance are important for assessing competitive athletes in practical and research settings. We present here a review of rowing performance measures, focusing on the errors in these measures and the implications for testing rowers. The yardstick for assessing error in a performance measure is the random variation (typical or standard error of measurement) in an elite athlete's competitive performance from race to race: ∼1.0% for time in 2000 m rowing events. There has been little research interest in on-water time trials for assessing rowing performance, owing to logistic difficulties and environmental perturbations in performance time with such tests. Mobile ergometry via instrumented oars or rowlocks should reduce these problems, but the associated errors have not yet been reported. Measurement of boat speed to monitor on-water training performance is common; one device based on global positioning system (GPS) technology contributes negligible extra random error (0.2%) in speed measured over 2000 m, but extra error is substantial (1-10%) with other GPS devices or with an impeller, especially over shorter distances. The problems with on-water testing have led to widespread use of the Concept II rowing ergometer. The standard error of the estimate of on-water 2000 m time predicted by 2000 m ergometer performance was 2.6% and 7.2% in two studies, reflecting different effects of skill, body mass and environment in on-water versus ergometer performance. However, well trained rowers have a typical error in performance time of only ∼0.5% between repeated 2000 m time trials on this ergometer, so such trials are suitable for tracking changes in physiological performance and factors affecting it. Many researchers have used the 2000 m ergometer performance time as a criterion to identify other predictors of rowing performance. Standard errors of the estimate vary widely between studies even for the same predictor, but the lowest errors (~1-2%) have been observed for peak power output in an incremental test, some measures of lactate threshold and measures of 30-second all-out power. Some of these measures also have typical error between repeated tests suitably low for tracking changes. Combining measures via multiple linear regression needs further investigation. In summary, measurement of boat speed, especially with a good GPS device, has adequate precision for monitoring training performance, but adjustment for environmental effects needs to be investigated. Time trials on the Concept II ergometer provide accurate estimates of a rower's physiological ability to output power, and some submaximal and brief maximal ergometer performance measures can be used frequently to monitor changes in this ability. On-water performance measured via instrumented skiffs that determine individual power output may eventually surpass measures derived from the Concept II.

year: 2012

title: Kaupapa Māori and a new curriculum in Aotearoa/New Zealand

authors: Chalmers, Lex

subjects: curriculum review

abstract: While geographical education is our focus in this paper, the broader colonial history of education is the backdrop against which we first view the principles of Māori geographies in education. The essay underscores the importance of ‘authenticity’, the participation of local communities and local studies connected to local environments and histories. We use an educational program of the Raglan Area School on Whaingaroa Harbour as an illustrative example. The geographies of Whaingaroa Harbour provide an exemplary context for programs in geographical education and we suggest that the new curriculum in both English and Te Reo Māori (Māori language) can enhance the movement towards bi-cultural education in Aotearoa/New Zealand. Our argument is that the 2007 curriculum creates the opportunity; the impediments lie in providing appropriate resources and developing community support for the delivery of the bicultural educational approaches. is an important issue in debates about educational policy and implementing a new curriculum in Aotearoa/New Zealand. This paper explores how the development of the 2007 curriculum in Aotearoa/New Zealand attempted to address curriculum, teaching and learning options for Māori. Māori are a significant national community with needs and aspirations in education. Māori have tangata whenua status in Aotearoa/New Zealand, where this term acknowledges the arrival and settlement of migrant people of the Pacific centuries prior to significant European colonization in the 19th Century. While progress has been made in Māori education since the significant Treaty of Waitangi Act in 1975, we wish to explore the potential of Kaupapa Māori (Māori practice) in the development of a new curriculum, Te Marautanga o Aotearoa.

text: Kaupapa Māori and a new curriculum in Aotearoa/New Zealand While geographical education is our focus in this paper, the broader colonial history of education is the backdrop against which we first view the principles of Māori geographies in education. The essay underscores the importance of ‘authenticity’, the participation of local communities and local studies connected to local environments and histories. We use an educational program of the Raglan Area School on Whaingaroa Harbour as an illustrative example. The geographies of Whaingaroa Harbour provide an exemplary context for programs in geographical education and we suggest that the new curriculum in both English and Te Reo Māori (Māori language) can enhance the movement towards bi-cultural education in Aotearoa/New Zealand. Our argument is that the 2007 curriculum creates the opportunity; the impediments lie in providing appropriate resources and developing community support for the delivery of the bicultural educational approaches. is an important issue in debates about educational policy and implementing a new curriculum in Aotearoa/New Zealand. This paper explores how the development of the 2007 curriculum in Aotearoa/New Zealand attempted to address curriculum, teaching and learning options for Māori. Māori are a significant national community with needs and aspirations in education. Māori have tangata whenua status in Aotearoa/New Zealand, where this term acknowledges the arrival and settlement of migrant people of the Pacific centuries prior to significant European colonization in the 19th Century. While progress has been made in Māori education since the significant Treaty of Waitangi Act in 1975, we wish to explore the potential of Kaupapa Māori (Māori practice) in the development of a new curriculum, Te Marautanga o Aotearoa.

year: 2010