title: Structural studies of some compounds containing C₂ fragments attached to various metal-ligand end-groups

authors: Bruce, Michael I.

subjects: C₂ ligands

abstract: The preparation, characterisation and single-crystal XRD molecular structure determinations of four complexes containing –CC–MLn end-groups, namely Ru{C≡CFc′(I)}(dppe)Cp (1), the vinylidene [Os(=C=CH₂)(PPh₃)₂Cp]PF₆ (2), trans-Pt(C≡CC₆H₄-4-C≡CPh){C≡CC₆H₄-4-C₂Ph[Co₂(μ-dppm)(CO)₄]}(PPh₃)₂ (3), and C₆H₄{μ₃-C₂[AuRu₃(CO)₉(PPh₃)]}₂-1,4 (4) are reported. In these compounds a range of –CC– environments is found, extending from the σ-bonded alkynyl group in 1 to examples where the C₂ unit interacts with either a proton (in vinylidene 2), by bridging a dicobalt carbonyl moiety (in 3) or the AuRu₃ cluster in 4. Changes in geometry are rationalised by considering the various bonding modes.

text: Structural studies of some compounds containing C₂ fragments attached to various metal-ligand end-groups The preparation, characterisation and single-crystal XRD molecular structure determinations of four complexes containing –CC–MLn end-groups, namely Ru{C≡CFc′(I)}(dppe)Cp (1), the vinylidene [Os(=C=CH₂)(PPh₃)₂Cp]PF₆ (2), trans-Pt(C≡CC₆H₄-4-C≡CPh){C≡CC₆H₄-4-C₂Ph[Co₂(μ-dppm)(CO)₄]}(PPh₃)₂ (3), and C₆H₄{μ₃-C₂[AuRu₃(CO)₉(PPh₃)]}₂-1,4 (4) are reported. In these compounds a range of –CC– environments is found, extending from the σ-bonded alkynyl group in 1 to examples where the C₂ unit interacts with either a proton (in vinylidene 2), by bridging a dicobalt carbonyl moiety (in 3) or the AuRu₃ cluster in 4. Changes in geometry are rationalised by considering the various bonding modes.

year: 2011

title: Benthic foraminiferal response to changes in bottom-water oxygenation and organic carbon flux in the eastern Mediterranean during LGM to Recent times

authors: Abu-Zied, Ramadan H.

subjects: benthic foraminifera

abstract: We present a high-resolution study of benthic foraminiferal abundances in 4 cores from the central Aegean and NE Levantine Seas, spanning the interval from 30 ka BP to the present. The benthic foraminiferal faunas indicate that during LGM times, bottom waters were well ventilated, while organic flux to the sea floor was significantly higher than today. From 30 to 10.2 ka BP, faunal density and composition suggest a gradual decrease in organic flux to the sea floor. This trend is interrupted by a short return to higher organic flux levels during the Younger Dryas (12.8–11.5 ka BP). The faunas immediately preceding the early to middle Holocene organic-rich layer (sapropel) S1 are very similar to Late Holocene faunas, indicating oligotrophic conditions. The transition from well ventilated bottom waters to anoxic (Levantine Basin) or strongly dysoxic (Aegean Sea) bottom waters appears to take place within a time-span of only 600 years, from ∼ 10.8 to 10.2 ka BP. Sapropel S1 (10.2–6.4 ka BP) is characterized by extended periods of bottom-water anoxia in the Levantine Basin, and by strongly dysoxic conditions punctuated by episodic re-ventilation events in the Aegean Sea. Re-establishment of fully oxygenated bottom-water conditions after sapropel S1 was extremely rapid. The ensuing Late Holocene faunas are very similar to recent faunas found in the Aegean Sea, suggesting much lower fluxes of organic matter to the sea floor than during glacial times.

text: Benthic foraminiferal response to changes in bottom-water oxygenation and organic carbon flux in the eastern Mediterranean during LGM to Recent times We present a high-resolution study of benthic foraminiferal abundances in 4 cores from the central Aegean and NE Levantine Seas, spanning the interval from 30 ka BP to the present. The benthic foraminiferal faunas indicate that during LGM times, bottom waters were well ventilated, while organic flux to the sea floor was significantly higher than today. From 30 to 10.2 ka BP, faunal density and composition suggest a gradual decrease in organic flux to the sea floor. This trend is interrupted by a short return to higher organic flux levels during the Younger Dryas (12.8–11.5 ka BP). The faunas immediately preceding the early to middle Holocene organic-rich layer (sapropel) S1 are very similar to Late Holocene faunas, indicating oligotrophic conditions. The transition from well ventilated bottom waters to anoxic (Levantine Basin) or strongly dysoxic (Aegean Sea) bottom waters appears to take place within a time-span of only 600 years, from ∼ 10.8 to 10.2 ka BP. Sapropel S1 (10.2–6.4 ka BP) is characterized by extended periods of bottom-water anoxia in the Levantine Basin, and by strongly dysoxic conditions punctuated by episodic re-ventilation events in the Aegean Sea. Re-establishment of fully oxygenated bottom-water conditions after sapropel S1 was extremely rapid. The ensuing Late Holocene faunas are very similar to recent faunas found in the Aegean Sea, suggesting much lower fluxes of organic matter to the sea floor than during glacial times.

year: 2008

title: Teachers' perceptions of the effectiveness of the Whānau Rūmaki teacher education programme, 1990-1992

authors: Kana, Fred

subjects: Maori Language

abstract: In 1990 the School of Education, the University of Waikato, initiated a special option within its regular pre-service teacher training programmes, an option designed to prepare teachers to deliver the New Zealand curriculum in bilingual and total immersion schools through the medium of te reo Māori. This alternative programmed, designated Whānau Rūmaki, was experimental and evolutionary. Inevitably particular elements of it had to be varied with each year's operation as its architects attempted 'to get the mix right'. It is difficult, however, when engaged in the day to day running of a programme, to stand back and review with any degree of objectivity its strengths and weaknesses. This study, therefore, in retrospect attempts to do three things: one, to follow the initial Whānau Rūmaki student cohort through its three or four year training cycle noting especially the difficulties confronting individual students some of whom dropped out of the programme; two, to gather information from as many as possible of the graduates who graduated about how well they felt they had been prepared for the rigours of classroom teaching; three, to be able, after analysing the data gathered, to recommend ways of improving the on-going Whānau Rūmaki programme.

text: Teachers' perceptions of the effectiveness of the Whānau Rūmaki teacher education programme, 1990-1992 In 1990 the School of Education, the University of Waikato, initiated a special option within its regular pre-service teacher training programmes, an option designed to prepare teachers to deliver the New Zealand curriculum in bilingual and total immersion schools through the medium of te reo Māori. This alternative programmed, designated Whānau Rūmaki, was experimental and evolutionary. Inevitably particular elements of it had to be varied with each year's operation as its architects attempted 'to get the mix right'. It is difficult, however, when engaged in the day to day running of a programme, to stand back and review with any degree of objectivity its strengths and weaknesses. This study, therefore, in retrospect attempts to do three things: one, to follow the initial Whānau Rūmaki student cohort through its three or four year training cycle noting especially the difficulties confronting individual students some of whom dropped out of the programme; two, to gather information from as many as possible of the graduates who graduated about how well they felt they had been prepared for the rigours of classroom teaching; three, to be able, after analysing the data gathered, to recommend ways of improving the on-going Whānau Rūmaki programme.

year: 1997