Development and use of computer techniques in x-ray crystallographic studies

The crystal and molecular structures of four chemically unrelated compounds have been determined by X-ray crystallography. One compound is organometallic and it crystallises in a centrosymmetric space group while the others are organic and their space groups are non-centrosymmetric. The compound bis(triphenylarsine)hexafluorobuta-1,3-diene platinum crystallises in two forms. Traditional vector methods were used to solve the structure of the isomer reported here. This is a further example of an organometallic compound where an olefin, in this case hexafluorobutadiene, is co-ordinated to the metal atom by one olefin bond to form what may be described as a 'metallo-cyclopropane'ring. Direct methods were used to determine the structures of 1,1-dichloro-2,5-diphenylcyclopropabenzene and 4,5,6-tri-O-benzoyl-2,3-di-S-ethyl-2,3-dithio-D-allose diethyl dithioacetal. In the first of these compounds the cyclopropabenzene system is not quite planar and the phenyl substituents are twisted and bent from the plane of the benzene ring in the cyclopropabenzene system. The second of these analyses confirmed the molecular configuration of the tetra-thio aldose derivative as D-allo and established that the molecule has a bent-chain conformation similar to that found in solution. The conformation of a brominated compound, extracted as an acetate derivative of formula C₃₂H₅₅O₈Br from the seaweed species Laurencia thyrsifera, has been established. The compound's structure is related to squalene and was solved using Vector methods. In addition to these analyses unsuccessful attempts to solve the crystal structures of a dinitro-imidazole derivative (C₄H₄N₄O₄) and a compound thought possibly to be a tetracyclo-decane (C₁₅H₁₂N₄) are outlined. A significant part of this project involved the further development of the X-ray crystallographic program suite of the University of Canterbury which is used in all X-ray structure analyses. Particular projects contributing to this development are discussed

Has the computing competence of first year university students increased during the last decade?

Computers have become ubiquitous. The perception is that they are used effectively and with authority by much of the younger population. Previous generations used computers to manipulate data, mainly in employment. The current generation considers use of computers to be part of their social life. This paper reports on the results of a longitudinal study of students in an introductory computing class at Lincoln University. Results from 1999 were compared with results from 2008 to see if there were any differences in the overall computing confidence reported by students from both cohorts. The computing activities of the 1999 and 2008 students have been compared. Results show that the current students are more likely to be computing online and their overall confidence is higher than in the earlier study. This confidence is not matched by increased skills in offline computing. There is some evidence that the 2008 students are less competent users of productivity software such as spreadsheets and databases than the 1999 students

The digital divide: real or imaginary?

There has been much written about the existence of a gap between generations when it comes to technology use and knowhow. This gap has been called the "digital divide." Since the early 1990s the prevalence of home computer use and ownership has increased to become the norm. Along with this, children are being exposed to computers at all levels of the education system from pre-school to tertiary study. This exposure has, in part, lead to the premise that this current generation are "good" at using computers. This paper examines the concept of the digital divide from the perspective of a class of students enrolling in an introductory computing class in a New Zealand University in 2009. The mean age of this class was 20 with the most represented age group being those who are younger than twenty. This study found little evidence of the traditional digital divide

Biological correlates of mental health: can oxytocin, cortisol and omega-3 fatty acids improve our understanding of treatment avoidance, behavioural withdrawal and cognitive changes accompanying depressive symptoms?

Abstract of a conference presentation

Up-Regulation of Mitochondrial Antioxidant Superoxide Dismutase Underpins Persistent Cardiac Nutritional-Preconditioning by Long Chain n-3 Polyunsaturated Fatty Acids in the Rat

Reactive oxygen species paradoxically underpin both ischaemia/reperfusion (I/R) damage and ischaemic preconditioning (IPC) cardioprotection. Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA) are highly susceptible to peroxidation, but are paradoxically cardioprotective. This study tested the hypothesis that LCn-3 PUFA cardioprotection is underpinned by peroxidation, upregulating antioxidant activity to reduce I/R-induced lipid oxidation, and the mechanisms of this nutritional preconditioning contrast to mechanisms of IPC. Rats were fed: fish oil (LCn-3 PUFA); sunflower seed oil (n-6 PUFA); or beef tallow (saturated fat, SF) enriched diets for six weeks. Isolated hearts were subject to: 180 min normoxic perfusion; a 30 min coronary occlusion ischaemia protocol then 120 min normoxic reperfusion; or a 3 × 5 min global IPC protocol, 30 min ischaemia, then reperfusion. Dietary LCn-3 PUFA raised basal: membrane docosahexaenoic acid (22:6n-3 DHA); fatty acid peroxidisability index; concentrations of lipid oxidation products; and superoxide dismutase (MnSOD) activity (but not CuZnSOD or glutathione peroxidase). Infarct size correlated inversely with basal MnSOD activity (r2 = 0.85) in the ischaemia protocol and positively with I/R-induced lipid oxidation (lipid hydroperoxides (LPO), r2 = 0.475; malondialdehyde (MDA), r2 = 0.583) across ischaemia and IPC protocols. While both dietary fish oil and IPC infarct-reduction were associated with reduced I/R-induced lipid oxidation, fish oil produced nutritional preconditioning by prior LCn-3 PUFA incorporation and increased peroxidisability leading to up-regulated mitochondrial SOD antioxidant activity

An investigation of differences in mature and younger student's use of a computer-based learning package

Older or ""mature"" students are becoming a larger proportion of the student population in tertiary education. This study looked at the difference between mature and younger students' use of, and attitudes towards, a Computer Based Learning (CBL) package used in a first year Economics class. Surveys, interviews and automatic recording of package use were used to gather data. It was found that the mature students made significantly more use of the package than the younger students. Other interesting results included the pattern of use and the way the two groups viewed the package. The results have implications for the provision of CBL material for both groups

Does undergraduate performance in medical sciences predict overall performance in the first year medical school examinations?

Background: In a traditional medical programme prior academic performance is a good indicator for success. We aimed to determine whether performance in year one correlated with undergraduate performance in Medical Science in our integrated curriculum. Summary of work: Prior performance in anatomy, biochemistry and physiology was accessed for students who had attended the University of Wollongong for their undergraduate studies. Performance was correlated with examination results achieved in year 1. Summary of results: Seventy six students enrolled in Medicine (2007-2010), had completed their undergraduate degree at UOW taking subjects in anatomy (n=63), biochemistry (n=69) or physiology (n=69). Prior performance in each discipline significantly correlated (P\u3c0.0001) with overall performance in a year 1 integratedexamination (r2=0.33-anatomy, 0.21-biochemistry, 0.38- physiology). Current and prior performance was significantly correlated within each discipline, however, physiology (r2=0.31, P\u3c0.0001) correlated more strongly than anatomy (r2=0.07, P=0.04) or biochemistry (r2=0.08, P=0.017). Conclusions: Undergraduate performance in medical sciences correlated with academic performance in year 1. Undergraduate performance in physiology had the strongest correlation, suggesting that learning in physiology was able to prepare students for learning in an integrated curriculum. Take-home messages: Prior academic performance in medical science can be predictors of student performance in first year medical exams