Robust Estimates of Okun's Coefficient for South Africa

Persistently high unemployment in South Africa, especially in the face of improved economic conditions since 1994, begs the question: Does unemployment in South Africa respond to changes in output? When considering the linkages between output and unemployment, it is useful to decompose unemployment into its three components: structural, frictional and cyclical unemployment. Deficient aggregate demand gives rise to cyclical unemployment. Okun's law (1962) refers to the inverse relationship that exists between cyclical output and cyclical unemployment This paper estimates the relationship between economic activity (cyclical GDP) and changes in the unemployment rate (cyclical unemployment) for South Africa. A variety of detrending methods is used to decompose output and unemployment series into their trend and cyclical components. The paper also addresses the question of asymmetries in Okun's coefficient. The results indicate the presence of an Okun's law relationship in South Africa over the period 1970-2005 with more evidence in favour of asymmetries during recessions.

Efficient state-exploration

The exploration of states is an important element of many problems. Many problems share properties which allow the formulation of general strategies for state exploration. This article examines these strategies with reference to the problem of deadlock detection in labelled transition systems. The main issues are discussed and four major tasks are identified: state generation, scheduling, state storage, and state compaction. Empirical data is presented, optimizations and special restrictions are discussed and, finally, the results are generalized

Actions for local government excellence in intergovernmental relations in South Africa

Published ArticleThe Constitution of the Republic of South Africa, 1996 (Act 108 of 1996) and conclusive Acts analysed in this article reflects the process of local government democratization in South Africa. In this milieu, the importance of intergovernmental relations in South Africa as a determining factor in the democratization process is evident. It is further argued that the operational activities flowing from these Acts directly shape the success of intergovernmental relations. This article therefore investigates the decisive influence operational activities have on intergovernmental relations. The local government integrated development plan (IDP) in general and the specific assessment process in particular serves as an example in this research of the influence of these activities on intergovernmental relations. This article then identifies appropriate actions and examines the contribution of important role players and government institutions to promote and facilitate intergovernmental relations in South Africa in this challenging environment. The research finally focuses on the involvement of other external institutions, specifically the Intergovernmental Institute of South Africa (IGISA), and the endeavour to support the promotion and facilitation of excellence in intergovernmental relations in South Africa

Career identities of first-year female coloured students

It is a well-acknowledged fact that the role of women in society has been changing worldwide over recent decades and South Africa has not been exempt from this trend. Dramatic changes — politically, socially, economically and educationally — have occurred in South Africa since its first democratic, non-racial elections in 1994, which have affected the lives of all citizens. These changes have had major implications for South African women, also regarding their identities. This necessitates a re-evaluation of the prior conceptualisation of identity among women, an issue which has moved from the periphery of academic discourse to the centre. The objective in this research was to explore and describe the career identities of a group of first-year female coloured students in post-apartheid South Africa. A qualitative, explorative, descriptive and contextual research design was implemented. Using purposive sampling, data were collected during six focus group interviews with the students. The findings of the study are presented under four central themes which emerged, namely, the participants' perspectives on career issues; self-knowledge; factors influencing career identities and career choices; and concerns regarding career development. Finally, recommendations are presented in this regard.South African Journal of Education Vol. 27 (1) 2007: pp. 117-13

Parallel Recursive State Compression for Free

This paper focuses on reducing memory usage in enumerative model checking, while maintaining the multi-core scalability obtained in earlier work. We present a tree-based multi-core compression method, which works by leveraging sharing among sub-vectors of state vectors. An algorithmic analysis of both worst-case and optimal compression ratios shows the potential to compress even large states to a small constant on average (8 bytes). Our experiments demonstrate that this holds up in practice: the median compression ratio of 279 measured experiments is within 17% of the optimum for tree compression, and five times better than the median compression ratio of SPIN's COLLAPSE compression. Our algorithms are implemented in the LTSmin tool, and our experiments show that for model checking, multi-core tree compression pays its own way: it comes virtually without overhead compared to the fastest hash table-based methods.Comment: 19 page

3D-QSAR and docking studies of pentacycloundecylamines at the sigma-1 (σ1) receptor

Pentacycloundecylamine (PCU) derived compounds have been shown to be promising lead structures for the development of novel drug candidates aimed at a variety of neurodegenerative and psychiatric diseases. Here we show for the first time a 3D quantitative structure–activity relationship (3D-QSAR) for a series of aza-PCU-derived compounds with activity at the sigma-1 (r1) receptor. A comparative molecular field analysis (CoMFA) model was developed with a partial least squares cross validated (q2) regression value of 0.6, and a non-cross validatedr2 of 0.9. The CoMFA model was effective at predicting the sigma-1 activities of atest set with an r2 >0.7. We also describe here the docking of the PCU-derivedcompounds into a homology model of the sigma-1 (r1) receptor, which was developed to gain insight into binding of these cage compounds to the receptor. Based on docking studies we evaluated in a [3H]pentazocine binding assay anoxa-PCU, NGP1-01 (IC50 = 1.78 lM) and its phenethyl derivative (IC50 = 1.54 lM). Results from these studies can be used to develop new compounds with specific affinity for the sigma-1(r1)Web of Scienc

Group-as-a-whole as a context for studying individual behaviour: A group diagnostic intervention

Orientation: Traditionalists view group interventions from three perspectives: singletons, dyads and whole groups. The focus of this research was on interventions from the third perspective, that of the whole group, using a systems psychodynamic stance. Research purpose: The purpose of the research was to use group-as-a-whole to study individual behaviour in organisations.Motivation for the study: Team research and practice is not on a par with the complexities that teams actually experience. Traditional group interventions use humanistic and functionalistic paradigms that do not consider the unconscious functioning of groups. Interventions that use the system psychodynamic paradigm could address these dynamics because they study behaviour of individual group members in the context of the group-as-a-whole. Research design, approach and method: The researcher conducted action research in a publishing company. He used purposive sampling and analysed the data using qualitative content analysis.Main findings: The researcher found that the group-as-a-whole partly explains the behaviour of team members and that intervening from this perspective could improve negative relationships.Practical/managerial implications: Managers can use interventions that use the groupas- a-whole concept as a diagnostic intervention to study and possibly change the complex behavioural issues that team members experience.Contribution/value-add: The findings give one an understanding of the behaviour of individual group members when one views it from a systems psychodynamic stance. Furthermore, the researcher proposes a group diagnostic intervention that will allow some of the root causes of poor interpersonal behaviour to surface and group members to diagnose and take ownership of their own behaviour.</p

Emerging strategies of targeting lipoprotein lipase for metabolic and cardiovascular diseases

Although statins and other pharmacological approaches have improved the management of lipid abnormalities, there exists a need for newer treatment modalities especially for the management of hypertriglyceridemia. Lipoprotein lipase (LPL), by promoting hydrolytic cleavage of the triglyceride core of lipoproteins, is a crucial node in the management of plasma lipid levels. Although LPL expression and activity modulation is observed as a pleiotropic action of some the commonly used lipid lowering drugs, the deliberate development of drugs targeting LPL has not occurred yet. In this review, we present the biology of LPL, highlight the LPL modulation property of currently used drugs and review the novel emerging approaches to target LPL

Khaos: Dynamically Optimizing Checkpointing for Dependable Distributed Stream Processing

Distributed Stream Processing systems are becoming an increasingly essential part of Big Data processing platforms as users grow ever more reliant on their ability to provide fast access to new results. As such, making timely decisions based on these results is dependent on a system's ability to tolerate failure. Typically, these systems achieve fault tolerance and the ability to recover automatically from partial failures by implementing checkpoint and rollback recovery. However, owing to the statistical probability of partial failures occurring in these distributed environments and the variability of workloads upon which jobs are expected to operate, static configurations will often not meet Quality of Service constraints with low overhead. In this paper we present Khaos, a new approach which utilizes the parallel processing capabilities of virtual cloud automation technologies for the automatic runtime optimization of fault tolerance configurations in Distributed Stream Processing jobs. Our approach employs three subsequent phases which borrows from the principles of Chaos Engineering: establish the steady-state processing conditions, conduct experiments to better understand how the system performs under failure, and use this knowledge to continuously minimize Quality of Service violations. We implemented Khaos prototypically together with Apache Flink and demonstrate its usefulness experimentally

Co-constructing Appreciative Inquiry across disciplines: A duo-ethnography

Orientation: Appreciative Inquiry (AI) has become increasingly popular as a tool for change management in the world of business and is spilling over into a range of contexts, linking a diversity of disciplines. However, instances where management has used AI in consultation with education for collaborative purposes could not be traced as yet. Research purpose: The aim of this study was for two AI practitioners, one in the field of Industrial and Organisational Psychology and one in Education, to partake in a collaborative study proceeding from reflection on the said researchers’ experiences with facilitating AI in different contexts. Motivation for the study: With social constructionism as a core principle underlying AI, it is argued that sharing experiences across disciplines could enrich the literature and the application of AI in different contexts. Research design, approach and method: The research is based on a qualitative, empirical, duo-ethnography using self-reflective narratives of the experiences of facilitating AI in cross-disciplinary contexts. Main findings: Reflecting on experiences in various disciplines lead to the co-construction of new knowledge. Not only were similar experiences supported, validated and extended, thus affirming the strength-based principle of AI, but it also provided the opportunity for disciplinary cross-fertilisation by combining different perspectives regarding the formality of the AI process and the extent of the facilitator’s and participants readiness to work with AI methodology. Practical/managerial implications: The formality of the AI process and hence the extent of the facilitator’s involvement (signalling his or her readiness to participate actively and take the lead in co-creating a new reality) must be tempered by due allowance for the participant’s readiness to work with AI methodology. Furthermore, participants should be accommodated within the psychological space where they find themselves at the moment when the intended intervention is initiated. Contribution/value-add: Duo-ethnography provided the researchers with the opportunity to challenge the ‘other’ to reflect on their own discipline-related AI experiences, in a deeper, more relational and authentic way. The voices and ideas identified and presented counter narratives, also blended in unique ways to augment the definition of AI as a multidisciplinary force to co-create a better society. More specifically, the ‘readiness’ of the facilitator for an AI encounter was conceptualised and applied to the psychological and behavioural readiness of not only the participants, but also the facilitators of AI workshops