The constitutional right to freedom of expression: how enforceable are school dress codes?

The constitutional changes in South Africa over the past decade have had far-reaching consequences on society. As organs of state, schools have been directly affected by the need to ensure that their operations and rules are constitutionally and legislatively compatible. Human rights do not exist purely as an ideal but must be promoted and enforced within the school sphere. One such right is the right to freedom of expression, and expression in the form of dress is a critical element of such expression within the school context. The issue of school dress codes in South Africa is examined with reference to the experiences of four other countries, in order to determine the constitutionality of such dress codes, and whether dress codes are an impermissible limitation of learners' freedom of expression, couched in permissible sounding language. South African Journal of Education Vol.23(3) 2003: 163-16

Cannabis and other variables affecting age at onset in a schizophrenia founder population

Objective: An ongoing collaborative study between the Human Neurogenetic Laboratory of Rockefeller University, New York and the Department of Psychiatry at the University of Pretoria, has been taking place since 1997, to map genes for schizophrenia. Aspects of cannabis use/abuse will be reported.Method: The Diagnostic Interview for Genetic Studies [DIGS] is used for all diagnosis. A narrative report is completed. From this database we determined: gender, diagnostic subtype, age of illness onset, early insults, early deviant behaviour, cannabis use/abuse and family history of schizophrenia.Results: From 341 subjects we found: 61% [n=209] males and 39% [n=132] females. In males, 75% [n=156] had schizophrenia and 25% [n=53] schizoaffective disorder[SADJ]. In females 74% [n=97] had schizophrenia and 26% [n=35] SAD. 35% of subjects, [n=118], 44% [n=91] males and 20% [n=27] female's used/abused cannabis. The mean age at onset of illness for the males was 20.5 years. This is significantly earlier than that of males with no cannabis use/abuse group as well as for both these groups in females. The long-term course of illness was similar in both cannabis use/abuse and non-use/abuse groups. An analysis of variance was used to determine the contribution of different factors in determining the age of criteria onset. According to the results obtained, early deviant behaviour was the most important determining age of criteria onset. The group with the lowest mean age of criteria were male users of cannabis with severe early deviant behaviour [18,4 years]. Conclusion: Cannabis use/abuse is common amongst male schizophrenia subjects, and affects age at onset of illness. Early deviant behaviour in the first ten years of life in these subjects is more important in this regard, and may be seen as a possible endophenotypical marker. Keywords: cannabis, psychosis, schizophrenia, founder population South African Psychiatry Review Vol. 9(2) 2006: 99-10

A Contextual Analysis of the Hate Speech Provisions of the Equality Act

The article presents a detailed contextual analysis of the categorical prohibition of hate speech in terms of section 10(1) of the Equality Act. It is argued that this provision is not primarily intended to describe and effectively regulate the extreme expression that falls within the narrow ambit of "hate speech" as defined in section 16(2)(c) of the Constitution. Rather, it is concerned with the promotion of equality in the broad societal context. It acknowledges the hurt and harm that discriminatory expression may entail and it condemns the reinforcement of systemic discrimination by means of expression. Therefore, the principal interpretive frame of reference for the analysis of section 10(1) of the Equality Act is the explicit constitutional obligation in terms of sections 9(3) and (4) of the Constitution to enact legislation to prevent and prohibit unfair discrimination, and not section 16(2)(c) of the Constitution. The fact that section 10(1) categorically prohibits hate speech, instead of premising its prohibition on the unfairness analysis generally applicable to discrimination in other contexts, however, implies that only expression with no reasonable prospect of meeting the constitutional fairness standard ought to be covered by section 10. Put differently, the prohibited expression may in no way promote rather than jeopardise the achievement of equality. The interpretation takes into account that section 10(1) applies only to engagement in expression that, in terms of an objective reasonableness assessment, is clearly primarily aimed at hurting or harming others, or at inciting others to hurt or harm, or at promoting hatred based on group identity. Furthermore, bona fide expression in accordance with the essential characteristics of the freedoms of expression mentioned in section 16(1) of the Constitution is explicitly excluded from its ambit. An analysis of the expression covered by section 10(1) leads to a conclusion that it prohibits only low-value discriminatory expression that obstructs the constitutional quest for the healing of our injured society. It manages to achieve this without jeopardising the constitutional guarantee of freedom of expression, construed in the light of the foundational values of the Constitution.   

Characteristic Evolution and Matching

I review the development of numerical evolution codes for general relativity based upon the characteristic initial value problem. Progress in characteristic evolution is traced from the early stage of 1D feasibility studies to 2D axisymmetric codes that accurately simulate the oscillations and gravitational collapse of relativistic stars and to current 3D codes that provide pieces of a binary black hole spacetime. Cauchy codes have now been successful at simulating all aspects of the binary black hole problem inside an artificially constructed outer boundary. A prime application of characteristic evolution is to extend such simulations to null infinity where the waveform from the binary inspiral and merger can be unambiguously computed. This has now been accomplished by Cauchy-characteristic extraction, where data for the characteristic evolution is supplied by Cauchy data on an extraction worldtube inside the artificial outer boundary. The ultimate application of characteristic evolution is to eliminate the role of this outer boundary by constructing a global solution via Cauchy-characteristic matching. Progress in this direction is discussed.Comment: New version to appear in Living Reviews 2012. arXiv admin note: updated version of arXiv:gr-qc/050809

Population genomics of domestic and wild yeasts

The natural genetics of an organism is determined by the distribution of sequences of its genome. Here we present one- to four-fold, with some deeper, coverage of the genome sequences of over seventy isolates of the domesticated baker's yeast, _Saccharomyces cerevisiae_, and its closest relative, the wild _S. paradoxus_, which has never been associated with human activity. These were collected from numerous geographic locations and sources (including wild, clinical, baking, wine, laboratory and food spoilage). These sequences provide an unprecedented view of the population structure, natural (and artificial) selection and genome evolution in these species. Variation in gene content, SNPs, indels, copy numbers and transposable elements provide insights into the evolution of different lineages. Phenotypic variation broadly correlates with global genome-wide phylogenetic relationships however there is no correlation with source. _S. paradoxus_ populations are well delineated along geographic boundaries while the variation among worldwide _S. cerevisiae_ isolates show less differentiation and is comparable to a single _S. paradoxus_ population. Rather than one or two domestication events leading to the extant baker's yeasts, the population structure of _S. cerevisiae_ shows a few well defined geographically isolated lineages and many different mosaics of these lineages, supporting the notion that human influence provided the opportunity for outbreeding and production of new combinations of pre-existing variation

Three little pieces for computer and relativity

Numerical relativity has made big strides over the last decade. A number of problems that have plagued the field for years have now been mostly solved. This progress has transformed numerical relativity into a powerful tool to explore fundamental problems in physics and astrophysics, and I present here three representative examples. These "three little pieces" reflect a personal choice and describe work that I am particularly familiar with. However, many more examples could be made.Comment: 42 pages, 11 figures. Plenary talk at "Relativity and Gravitation: 100 Years after Einstein in Prague", June 25 - 29, 2012, Prague, Czech Republic. To appear in the Proceedings (Edition Open Access). Collects results appeared in journal articles [72,73, 122-124

Mutations in a Guanylate Cyclase GCY-35/GCY-36 Modify Bardet-Biedl Syndrome–Associated Phenotypes in Caenorhabditis elegans

Ciliopathies are pleiotropic and genetically heterogeneous disorders caused by defective development and function of the primary cilium. Bardet-Biedl syndrome (BBS) proteins localize to the base of cilia and undergo intraflagellar transport, and the loss of their functions leads to a multisystemic ciliopathy. Here we report the identification of mutations in guanylate cyclases (GCYs) as modifiers of Caenorhabditis elegans bbs endophenotypes. The loss of GCY-35 or GCY-36 results in suppression of the small body size, developmental delay, and exploration defects exhibited by multiple bbs mutants. Moreover, an effector of cGMP signalling, a cGMP-dependent protein kinase, EGL-4, also modifies bbs mutant defects. We propose that a misregulation of cGMP signalling, which underlies developmental and some behavioural defects of C. elegans bbs mutants, may also contribute to some BBS features in other organisms

Physics, Astrophysics and Cosmology with Gravitational Waves

Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers), and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.Comment: 137 pages, 16 figures, Published version <http://www.livingreviews.org/lrr-2009-2