Mapping unstructured mesh codes onto local memory parallel architectures

Initial work on mapping CFD codes onto parallel systems focused upon software which employed structured meshes. Increasingly, many large scale CFD codes are being based upon unstructured meshes. One of the key problems when implementing such large scale unstructured problems on a distributed memory machine is the question of how to partition the underlying computational domain efficiently. It is important that all processors are kept busy for as large a proportion of the time as possible and that the amount, level and frequency of communication should be kept to a minimum. Proposed techniques for solving the mapping problem have separated out the solution into two distinct phases. The first phase is to partition the computational domain into cohesive sub-regions. The second phase consists of embedding these sub-regions onto the processors. However, it has been shown that performing these two operations in isolation can lead to poor mappings and much less optimal communication time. In this thesis we develop a technique which simultaneously takes account of the processor topology whilst identifying the cohesive sub-regions. Our approach is based on an unstructured mesh decomposition method that was originally developed by Sadayappan et al [SER90] for a hypercube. This technique forms a basis for a method which enables a decomposition to an arbitrary number of processors on a specified processor network topology. Whilst partitioning the mesh, the optimisation method takes into account the processor topology by minimising the total interprocessor communication. The problem with this technique is that it is not suitable for dealing with very large meshes since the calculations often require prodigious amounts of computing processing power. The problem can be overcome by creating clusters of the original elements and using this to create a reduced network which is homomorphic to the original mesh. The technique can now be applied to the image network with comparative ease. The clusters are created using an efficient graph bisection method. The coarseness of the reduced mesh inevitably leads to a degradation of the solution. However, it is possible to refine the resultant partition to recapture some of the richness of the original mesh and hence achieve reasonable partitions. One of the issues to be addressed is the level of granuality to obtain the best balance between computational efficiency and optimality of the solution. Some progress has been made in trying to find an answer to this important issue. In this thesis, we show how the above technique can be effectively utilised in large scale computations. Results include testing the above technique on large scale meshes for complex flow domains

Reference Transcriptome for a Facultatively Eusocial Bee, Megalopta genalis

This article analyses gendering processes in two distinct models of work organization. It is a widespread belief that, compared to hierarchical (Tayloristic) organizations, team-based work offers opportunities for a high quality of working life to a broader range of employees, both men and women. Our research, however, suggests that gender inequality is (re)produced in both settings and results from the so-called gender subtext. The gender subtext is the set of often concealed power-based processes (re)producing gender distinction in social practices through organizational and individual arrangements. We draw a comparison between the gender subtext of Tayloristic and team-based work organizations through a theoretical analysis, illustrated by empirical data concerning the functioning of the gender subtext in organizations in the Dutch banking sector. Taylorism and team-based work differ in their conceptualization of organization and job design, but, when it comes to the gender subtext, it is six of one and half a dozen of the other. We argue that in both approaches a gender subtext contributes to the emergence of different but gendered notions of the ‘disembodied worker’. In both cases the notion of the abstract worker is implicitly loaded with masculine connotations. This gender bias is supported by two factors influencing the gendering of jobs: the gender connotations of care responsibilities and of qualification profiles. These implicit connotations produce and reinforce unequal opportunities for men and women to get highly qualified or management jobs. Our research, therefore, questions the self-evidence of stating that team-based work will offer opportunities for a higher quality of working life for women

Point-of-care in Aboriginal hands

Diabetes, kidney disease and heart disease (all chronic diseases) are among the most serious health problems facing Aboriginal people today. The point-of-care program has a broad chronic disease focus that (a) looks for early signs of diabetes, kidney disease and heart disease collectively and (b) provides follow-up management for people identified as being at risk for chronic disease

Brain microRNAs among social and solitary bees

Evolutionary transitions to a social lifestyle in insects are associated with lineage-specific changes in gene expression, but the key nodes that drive these regulatory changes are unknown. We examined the relationship between social organization and lineage-specific microRNAs (miRNAs). Genome scans across 12 bee species showed that miRNA copy-number is mostly conserved and not associated with sociality. However, deep sequencing of small RNAs in six bee species revealed a substantial proportion (20–35%) of detected miRNAs had lineage-specific expression in the brain, 24–72% of which did not have homologues in other species. Lineage-specific miRNAs disproportionately target lineage-specific genes, and have lower expression levels than shared miRNAs. The predicted targets of lineage-specific miRNAs are not enriched for genes with caste-biased expression or genes under positive selection in social species. Together, these results suggest that novel miRNAs may coevolve with novel genes, and thus contribute to lineage-specific patterns of evolution in bees, but do not appear to have significant influence on social evolution. Our analyses also support the hypothesis that many new miRNAs are purged by selection due to deleterious effects on mRNA targets, and suggest genome structure is not as influential in regulating bee miRNA evolution as has been shown for mammalian miRNAs