997 resultados para secondary constriction


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A strategy for the preparation of the otherwise difficult to obtain binary organometallic oxides containing two heavy main group elements is described and exemplified by the synthesis of [(p-MeOC6H4)2Te(OSnt-Bu2OH)2]2.

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The unsymmetrical1y substituted diorganotellurium dihalides [2-(4,4'-N02C6H4CHNC6H3Me]RTeX2 (R = 4-MeOC6H4, X = Cl,
1a; Br, 1b; I, 1c; R =4-MeC6H4 ; X = Cl, 2; R =C6H5, X = Cl, 3) were prepared in good yields and characterized by solution and solid-state 125Te NMR spectroscopy, IR spectroscopy and X-ray crystallography. In the solid-state, molecular structures of 1a and 1c possess scarcely observed 1,4-type intramolecular Te···N secondary interaction. Crystal packing of these compounds show an unusually rich diversity of intermolecular secondary, Te·· ·0, Te· .. \ and 1···1 interactions, Te·· ·π contacts as well as extensive
π-stacking of the organic substituents.

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The synthesis and characterization of unsymmetric diorganotellurium compounds containing a sterically demanding I-naphthyl or
mesitylligand and a small bite chelating organic ligand capable of 1,4-Te···N(O) intramolecular interaction is described. The reaction
of ArTeCl3 (Ar = I-ClOH7, Np; 2,4,6-Me3C6H2' Mes) with (SB)HgCI [SB = the Schiff base, 2-(4,4'-N02C6H4CH=NC6H3-Me)] or a methyl ketone (RCOCH3) afforded the corresponding dichlorides (SB)ArTeCI2 (Ar = Np, 1Aa; Mes, 1Ba) or (RCOCH2)ArTeCl2 (Ar = Np; R = Ph (2Aa), Me (3Aa), Np (4Aa); Ar = Mes, R = Ph (2Ba)). Reduction of 1Aa and 1Ba by Na2S205 readily gave the tellurides (SB)ArTe (Ar = Np (1A), Mes, (1B) but that of dichlorides derived from methylketones was complicated due to partial decomposition to tellurium powder and diarylditelluride (Ar2Te2), resulting in poor yields of the corresponding tellurides 2A, 2B and 3A. Oxidation of the isolated tellurides with S02Cl2, Br2 and I2 yielded the corresponding dihalides. All the synthesized compounds have been characterized with the help of IR, 1H, l3C, and 125Te NMR and in the case of 2Aa, and 2Ba by X-ray crystallography. Appearance of only one 125Te signal indicated that the unsymmetric derivatives were stable to disproportionation to symmetric species. Intramolecular 1,4-Te· . ·0 secondary bonding interactions (SBIs) are exhibited in the crystal structures of both the tellurium(IV) dichlorides, 2Aa, and 2Ba. Steric repulsion of the mesityl group in the latter dominates over lone pair-bond pair repulsion, resulting in significant widening of the equatorial C-Te-C angle. This appears to be responsible for the lack of Te· . ·CI involved supramolecular associations in the crystal structure of 2Ba.

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Resilient Families is a school-based prevention program designed to help students and parents develop knowledge, skills and support networks to promote health and wellbeing during the early years of secondary school. the program is designed to build within-family connectedness (parent--adolescent communication, conflict resolution) as well as improve social support between different families, and between families and schools. It is expected to promote social, emotional and academic competence and to prevent health and social problems in youth.

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The objective of this study was to investigate relationships between adolescent cannabis use and indices of parent - child attachment, family functioning and parent attitudes to drugs and delinquency. A total of 2848 year 9 and 2363 year 11 students participated in the Victorian Adolescent Health and Well-Being Survey (1999). The study was a school-based random sample of 535 metropolitan and rural, government and non-government secondary schools throughout Victoria, Australia. Cannabis use was defined as 'any' and 'weekly' use in the last 30 days. Multivariate logistic regression was used to identify independent associations between cannabis use and parent - child attachment, family functioning and parent attitudes to drugs and delinquency. Cannabis use in year 9 was associated with permissive parent attitudes to drugs and delinquency (any use: adjusted odds ratio (OR) = 8.1; weekly use: adjusted OR = 7.6), and was particularly sensitive to small changes in the quality of the parent - child relationship with risk increasing threefold for those describing their attachment as 'good' compared with 'very good' (any use: adjusted OR = 2.8, weekly use adjusted OR = 2.9). A similar, but more moderate pattern association was evident in year 11. After adjusting for other family and background factors, poor family functioning showed minimal association with level of cannabis use at both year levels. Results suggest that intervention efforts might sensibly target strengthening parent - children relationships and promoting less permissive parent attitudes to drug use.

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LSAY is a research program that follows young Australians as they move through secondary school, into further education or training, and into the labour market and adult life. This website provides access to the electronic full text versions of LSAY research reports, from 1996 to present.

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The Food and Move project was a collaborative project with the students, staff and parents from four Warrnambool secondary colleges which focussed on promoting healthy eating and physical activity in secondary schools and built capacity for ongoing health promotion to address overweight/obesity.

The project aimed to:

1. Increase awareness amongst students, parents and staff of the links between regular physical activity and good nutrition to achieve optimal health.
2. Increase awareness amongst students, parents and staff of childhood/adolescent obesity and its implications for future health.
3. Improve the opportunities for students to access healthy food at their school canteen.
4. Improve the opportunities for students to access physical activity at recess and lunchtime.
5. Prepare a resource package of initiatives for use in secondary colleges to support the provision of opportunities for healthy eating and physical activity at Warrnambool secondary colleges.
6. Support the development of appropriate physical activity and nutrition curricula.



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# 1. Introduction. Exploring the gender and IT problem and possible ways forward /​ Julianne Lynch
# 2. The imagined curriculum: who studies Computing and Information Technology subjects at the senior secondary level? /​ Margaret Vickers and My Trinh Ha
# 3. A question of attention: challenges for researching the under representation of girls in Computing and Information Technology subjects /​ Leonie Rowan
# 4. The nature and purpose of Computing and Information Technology subjects in the senior secondary school curriculum in New South Wales /​ Toni Downes
# 5. The social construction of Computing and Information Technology subject subculture /​ Catherine Harris
# 6. Boy nerds, girl nerds: constituting and negotiating Computing and Information Technology and peer groups as gendered subjects in schooling /​ Kerry Robinson and Cristyn Davies
# 7. CIT teachers' cultures in a globalising world /​ Carol Reid and Jose van der Akker
# 8. Perceptions of changing pedagogies in Computing and Information Technology /​ Susanne Gannon

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Discusses the transition from primary to secondary education in relation to mathematics. Discusses how to minimise the disruption and maximise the communication between, and effective outcomes for both levels of schooling, to help the students, while easing the professional demands placed on teachers.