Effect of first impressions on student evaluations of lecturers

Includes abstract.Includes bibliographical references.Academic institutions (particularly historically White tertiary institutions) are experiencing challenges in attracting and retaining Black African and femail academic staff. Anecdotal evidence suggests that Black African academic staff at historically White universities in South Africa experience more resistance from students than White staff do. This study consequently investigated whether students rate lecturers differently on first impression, based on the lecturers' and students' race and gender

Multi material powder delivering systems for selective laser melting

Published ArticleSelective Laser Melting (SLM) is a powder bed fusion process which is an additive manufacturing (AM) process, whereby a laser beam selectively fuses regions of a powder bed to form complex objects. Growth in the SLM field has revealed the need for parts containing multiple materials for applications in the medical, tool making, aerospace and other hi-tech industries. By applying multiple materials, regions with different mechanical properties, thermal conductivity zones or corrosion-resistant coatings can be achieved in a single manufacturing cycle utilizing the SLM process. With the SLM process physical bonds can be formed between different materials by creating an interlocking interface due to the rapid solidification of the molten materials. With the current SLM equipment, multi material objects are possible but only with material differences between the layers. New approaches are needed to develop a method that allows multi material parts not only in the Z axis, but also allow material differences on a single layer (X-Y axis). Approaches such as powder feeding through a capillary tube, auger feed system, electrostatic charge or masks have all been proposed as solutions to multi material deposition. Multi material objects produced in a single cycle with complex geometry and prescribed properties has the opportunity of further growing the AM market

A new species of Neocaeculus (Acari: Prostigmata: Caeculidae) from Barrow island, Western Australia, with a checklist of world Caeculidae

Neocaeculus imperfectus new species is described from material collected on Barrow Island, Western Australia. Keys to genera and Australasian species of Caeculidae are provided, and the relationship between the genera Neocaeculus and Microcaeculus is discussed. A checklist of species for Caeculidae is provided

Branching Subset Simulation

Subset Simulation is a Markov chain Monte Carlo method, initially conceived to compute small failure probabilities in structural reliability problems. This is done by iteratively sampling from nested subsets in the input space of a performance function. Subset Simulation has since been adapted as a sampler in other realms such as optimisation, Bayesian updating and history matching. In all of these contexts, it is not uncommon that either the geometry of the input domain or the nature of the corresponding performance function cause Subset Simulation to suffer from ergodicity problems. To address these problems, this paper proposes Branching Subset Simulation. The proposed framework dynamically partitions the input space, and recursively begins Branching Subset Simulation anew in each partition. It is shown that Branching Subset Simulation is less likely than Subset Simulation to suffer from ergodicity problems and has improved sampling efficiency in the presence of multi-modality

The effect of a 6-month cardiac rehabilitation programme on serum lipoproteins and apoproteins A1 and B and lipoprotein a

One hundred and forty-two cardiac rehabilitation patients were followed up over a p.eriod of 6 months and the percentage change over time was recorded for various lipid fractions including apoprotein AI (apo AI), apoprotein B (apo B) and lipoprotein a (Lp(a)). Data were analysed to see if improvement in peak oxygen consumption (V2) or changes in body weight were related to any of the above. A significant percentage change was found for peak Vo2, ventilatory threshold, highdensity lipoprotein cholesterol (HDLC) and triglyceride levels, total cholesterol (TC)/HDL ratio, apo AI, apo A/apo B ratio and Lp(a). Multiple regression analysis showed that alterations in the lipid fractions were not related to changes in physical fitness except in the case of TC levels which dropped independently of other measures. On multivariate analysis, Lp(a) correlated positively with both the Broca index and the use of drugs ofthe fibrate series.S Afr Med J1993; 83: 315-31

DNA Vaccines Encoding Antigen Targeted to MHC Class II Induce Influenza-Specific CD8+ T Cell Responses, Enabling Faster Resolution of Influenza Disease

Current influenza vaccines are effective but imperfect, failing to cover against emerging strains of virus and requiring seasonal administration to protect against new strains. A key step to improving influenza vaccines is to improve our understanding of vaccine induced protection. Whilst it is clear that antibodies play a protective role, vaccine induced CD8+ T cells can improve protection. To further explore the role of CD8+ T cells we used a DNA vaccine that encodes antigen dimerised to an immune cell targeting module. Immunising CB6F1 mice with the DNA vaccine in a heterologous prime boost regime with the seasonal protein vaccine improved the resolution of influenza disease compared to protein alone. This improved disease resolution was dependent on CD8+ T cells. However, DNA vaccine regimes that induced CD8+ T cells alone were not protective and did not boost the protection provided by protein. The MHC targeting module used was an anti-I-Ed single chain antibody specific to the BALB/c strain of mice. To test the role of MHC targeting we compared the response between BALB/c, C57BL/6 mice and an F1 cross of the two strains (CB6F1). BALB/c mice were protected, C57BL/6 were not and the F1 had an intermediate phenotype; showing that the targeting of antigen is important in the response. Based on these findings, and in agreement with other studies using different vaccines, we conclude that in addition to antibody, inducing a protective CD8 response is important in future influenza vaccines