Thermalization of a Lipkin-Meshkov-Glick model coupled to a bosonic bath

We derive a Lindblad master equation that approximates the dynamics of a Lipkin-Meshkov-Glick (LMG) model weakly coupled to a bosonic bath. By studying the time evolution of operators under the adjoint master equation we prove that, for large system sizes, these operators attain their thermal equilibrium expectation values in the long-time limit, and we calculate the rate at which these values are approached. Integrability of the LMG model prevents thermalization in the absence of a bath, and our work provides an explicit proof that the bath indeed restores thermalization. Imposing thermalization on this otherwise non-thermalizing model outlines an avenue towards probing the unconventional thermodynamic properties predicted to occur in ultracold-atom-based realizations of the LMG model.Comment: 10 pages, 3 figure

The development of a spatial decision support system to optimise agricultural resource use in the Western Cape

This paper describes the development of a decision support model for regional agricultural resource utilisation. The analysis was generated in a spatial context and the optimisation technique was interactive with a geographical information system (GIS). Economic and operational research methodologies were linked to the GIS in the process of determining the appropriate resource uses for the region. The optimisation technique was applied for the Western Cape Province for eight crops. The results of this research are discussed in this paper, with specific reference to its application value for the public sector and agri-business.Farm Management, Resource /Energy Economics and Policy,

Primary health care in the South African context – medical students\' perspectives

Background Both the South African Department of Health and the University of Cape Town (UCT) have committed to the primary health care (PHC) approach, which is best captured in the Declaration of Alma Ata. If medical students are to be trained in the PHC approach, it is important that they not only have a good understanding of this approach, but are also aware of the social, economic and political context that they will be working in when they have qualified, so that they can develop realistic expectations of their careers as doctors. From research that was conducted at UCT, this article covers UCT medical students' views of health care in South Africa, including their perceptions of the applicability and implementation of the PHC approach for South Africa, and their perceptions of how the South African government features in issues of health and the PHC approach. Methods Mixed-methods were used, but this article will focus on the qualitative data gathered. One hundred and seventeen medical students (years one to four) were purposively selected to be involved in focus groups and interviews. These focus groups were conducted between February 2004 and March 2005. Results Students acknowledged that the state of health care in South Africa needs to change and showed an awareness of the role that South Africa's history of apartheid has played in the state of health care in these areas and the existence of inequity. They however did not agree on the applicability of the PHC approach to the South African situation. The PHC approach is seen not to be working in South Africa because of various obstacles to its implementation and success, such as disorganisation within the health system, and a lack of infrastructure, finances and resources. There seemed to be a general understanding amongst the students that they will have been trained in the PHC approach but then will be working within a system that has possibly not undergone similar changes. Students agreed on the important role of government in PHC, some maintaining that the government should be at the forefront of its implementation, but were generally dissatisfied with the role the South African government is currently playing in health care. Conclusion It is encouraging that students are generally aware of the reality of health care in South Africa and of the fact that more change needs to take place. However, it may be that many students who have a limited understanding of the impact that apartheid had on health care provision in South Africa, and this could then impact on students' perceptions of the applicability of the current PHC approach for South Africa. Students' views that the PHC approach has not been fully implemented in South Africa are a concern, as it is these types of views that are likely to cause students to lose confidence in the PHC approach, and will most likely widen the disjuncture between theory of the approach and the reality of its implementation. Regarding the political dynamics of the PHC approach, students do need to be aware of political factors that can impact on the success of this approach. Discussion around and research into the social, economic and political context of health care and medical education has particular relevance for South Africa, and it is vital that students' views on these issues are acknowledged so that areas for change can be identified and addressed. South African Family Practice Vol. 49 (10) 2007: pp. 6-1

Primary health care in the South African context - medical students' perspectives

Background Both the South African Department of Health and the University of Cape Town (UCT) have committed to the primary health care (PHC) approach, which is best captured in the Declaration of Alma Ata. If medical students are to be trained in the PHC approach, it is important that they not only have a good understanding of this approach, but are also aware of the social, economic and political context that they will be working in when they have qualified, so that they can develop realistic expectations of their careers as doctors. From research that was conducted at UCT, this article covers UCT medical students' views of health care in South Africa, including their perceptions of the applicability and implementation of the PHC approach for South Africa, and their perceptions of how the South African government features in issues of health and the PHC approach. Methods Mixed-methods were used, but this article will focus on the qualitative data gathered. One hundred and seventeen medical students (years one to four) were purposively selected to be involved in focus groups and interviews. These focus groups were conducted between February 2004 and March 2005. Results Students acknowledged that the state of health care in South Africa needs to change and showed an awareness of the role that South Africa's history of apartheid has played in the state of health care in these areas and the existence of inequity. They however did not agree on the applicability of the PHC approach to the South African situation. The PHC approach is seen not to be working in South Africa because of various obstacles to its implementation and success, such as disorganisation within the health system, and a lack of infrastructure, finances and resources. There seemed to be a general understanding amongst the students that they will have been trained in the PHC approach but then will be working within a system that has possibly not undergone similar changes. Students agreed on the important role of government in PHC, some maintaining that the government should be at the forefront of its implementation, but were generally dissatisfied with the role the South African government is currently playing in health care. Conclusion It is encouraging that students are generally aware of the reality of health care in South Africa and of the fact that more change needs to take place. However, it may be that many students who have a limited understanding of the impact that apartheid had on health care provision in South Africa, and this could then impact on students' perceptions of the applicability of the current PHC approach for South Africa. Students' views that the PHC approach has not been fully implemented in South Africa are a concern, as it is these types of views that are likely to cause students to lose confidence in the PHC approach, and will most likely widen the disjuncture between theory of the approach and the reality of its implementation. Regarding the political dynamics of the PHC approach, students do need to be aware of political factors that can impact on the success of this approach. Discussion around and research into the social, economic and political context of health care and medical education has particular relevance for South Africa, and it is vital that students' views on these issues are acknowledged so that areas for change can be identified and addressed

Dynamics and Charge Fluctuations in Large-q Sachdev-Ye-Kitaev Lattices

It is known that the large-$q$ complex Sachdev-Ye-Kitaev (SYK) dot thermalizes instantaneously under rather general dynamical protocols. We consider a lattice of such dots coupled together, allowing for $r/2$ body hopping of particles between nearest neighbors. We develop a rather general analytical framework to study the dynamics to leading order in $1/q$ on such a lattice, allowing for arbitrary time dependent couplings, hence general dynamical protocols. We find that the physics of the diffusive case $r>2$ is effectively the same as the kinetic case $r=2$, assuming $r=\mathcal{O}(q^0)$. Remarkably, we find that the local charge densities $\mathcal{Q}_i$ form a closed set of equations. They however only show fluctuations of the order $\mathcal{O}(\mathcal{Q}_i/q)$, hence remaining constant in the limit $q\rightarrow \infty$. Despite this effective lack of charge dynamics, the dots do not in fact behave as isolated lattice sites which would thermalize instantaneously. Indeed, we show via a proof by contradiction that such instantaneously thermalize is not generally possible for a connected lattice. Importantly, the results are shown to be independent of the dimensionality of the lattice.Comment: 14 pages, 1 figur

Medical students' attitudes towards the primary healthcare approach - what are they and how do they change?

Background: The context of the research presented in this article is the new MBChB curriculum at the University of Cape Town (UCT) that has been in operation since 2002. This new curriculum is primary health care (PHC) driven and puts emphasis on the integration of biological and psychosocial elements. The context of curriculum reform at UCT can be placed within the broader South African context, in which the South African Department of Health has made a commitment to the PHC approach. The aim of this research was to provide an understanding of medical students’ attitudes towards the PHC approach. The findings presented in this article form part of a broader set of findings for a PhD research study aimed at qualitatively exploring medical students’ attitudes towards and perceptions of PHC. Methods: A qualitative approach was used and focus groups and interviews were conducted with second-, third- and fourth year medical students at UCT. A total of 82 students were purposively selected to participate in the research. A content analytic approach was used to analyse the focus group and interview data. Results: The students generally had a positive attitude towards the PHC approach and were positive about UCT’s decision to promote this approach. Some, however, were concerned about the international relevance and status of their degree, and concerns were also raised about the contrast between the theory and reality of the approach, with many labelling PHC as idealistic. The students’ responses indicated that their attitudes towards the PHC approach were open to change during the course of their academic career and were influenced by a range of factors. Some of these factors are related to the medical school environment, such as the PHC approach itself, how PHC is taught, and the views of other students and staff at UCT. Other factors that were not related to the university included personality, the students’ background and exposure to health facilities, and clinical exposure outside UCT. Conclusion: These findings raise the question of whether students are able to think and feel positively about the PHC approach, but not actually internalise the philosophy of the approach. The students’ struggle with the incongruence between what is perceived as the idealistic theory of PHC and the reality of health care in South Africa is also an issue that needs to be acknowledged. These issues have international relevance, and are particularly significant in South Africa, where a commitment has been made by the South African Department of Health to the PHC approach and where doctors are set to play a vital role in its implementation and success

Primary school teachers’ knowledge and misperceptions of attention deficit hyperactivity disorder (ADHD)

Putting inclusive education into practice and within diverse classrooms, teachers have to support and teach according to a variety of needs and preferences of learners, among them learners with ADHD. Teachers are seen as some of the most valuable sources of information with regard to referral and diagnosis of this disorder. They are also responsible for creating an environment that is conducive to academic, social and emotional success for children with ADHD. However, since there is some doubt as to whether teachers have the appropriate knowledge of ADHD to fulfill this important role, we aimed at assessing the knowledge and misperceptions of primary school teachers in towns on the periphery of the Cape Town Metropole. A quantitative study using a survey was conducted. The measuring scale used was the KADDS (Knowledge of Attention Deficit Disorders Scale), which measures teachers’ knowledge and misperceptions in three specific areas: symptoms/diagnosis of ADHD, general knowledge about the nature, causes and outcome of ADHD and possible interventions with regard to ADHD. The data were statistically analysed. Overall knowledge of ADHD was poor. The results suggest that teachers are most knowledgeable about symptoms/diagnosis, scoring lower on treatment and general knowledge subscales.Keywords: ADHD; attention deficit hyperactivity disorder; inclusive education; primary school teachers; teacher training; teachin

The Impact of Value-Orientations on Cross-cultural Encounters and Mediation: A Survey in Tanzania\'s Educational System

This article focuses on the impact of value-orientations on cross-cultural encounters and mediation in the Tanzanian educational system. The purpose of the article is to give an emic perspective on value-orientations in crosscultural encounters and mediation situations in the educational system, to improve understanding of the conflictive aspects of these encounters. To achieve this purpose, the aim of the article is to identify which valueorientations lead to conflicts and how these conflicts are managed. The article will, firstly, provide an overview on current value discourses and, secondly, prove the bilingual validity of value domains based on the Schwartz value model. Thirdly, methodology and empirical findings will be presented. The conclusion leads to recommendations for cross-cultural interactions between Europeans and Tanzanians.African Journal on Conflict Resolution Vol. 8 (1) 2008: pp. 39-7

PerfWeb: How to Violate Web Privacy with Hardware Performance Events

The browser history reveals highly sensitive information about users, such as financial status, health conditions, or political views. Private browsing modes and anonymity networks are consequently important tools to preserve the privacy not only of regular users but in particular of whistleblowers and dissidents. Yet, in this work we show how a malicious application can infer opened websites from Google Chrome in Incognito mode and from Tor Browser by exploiting hardware performance events (HPEs). In particular, we analyze the browsers' microarchitectural footprint with the help of advanced Machine Learning techniques: k-th Nearest Neighbors, Decision Trees, Support Vector Machines, and in contrast to previous literature also Convolutional Neural Networks. We profile 40 different websites, 30 of the top Alexa sites and 10 whistleblowing portals, on two machines featuring an Intel and an ARM processor. By monitoring retired instructions, cache accesses, and bus cycles for at most 5 seconds, we manage to classify the selected websites with a success rate of up to 86.3%. The results show that hardware performance events can clearly undermine the privacy of web users. We therefore propose mitigation strategies that impede our attacks and still allow legitimate use of HPEs

Sex discrimination in employment

This work deals with sex discrimination in employment. It traces the origins of discrimination and considers the meaning of equality and the role which the law can play in attaining equality in the work place. International and regional norms, as well as the British and American legal systems, are analysed. The position in South Africa is then considered against that background, and reforms are proposed. These include the formulation of comprehensive anti-discrimination legislation which draws upon the American and British systems, but is adapted to suit local needs. The establishment of an independent administrative body to monitor the legislation, as well as a specialised judicial body through which the legislation is to be enforced, is also proposed.School of LawThesis (LL.D.)--University of South Africa, 1992