A new genus of ovuliferous glossopterid fructifications from South Africa

Main articleA new genus of Early Permian glossopterid fructifications, Gladiopomum, is established to accommodate pedicellate, capitate fructifications with narrow receptacles, apical spines, and very broad wings. Two species recognized within this genus were previously assigned to Scutum Plumstead and Hirsutum Plumstead, viz., G. dutoitides (Plumstead) comb. nov. and G. acadarense (Anderson & Anderson) comb. nov. An additional species, G. elongatum sp. nov. is established based on material from a new fossil locality at Rietspruit Colliery in the northern Karoo Basin. All species of Gladiopomum are confined to the Vryheid Formation; the genus may constitute a useful biostratigraphic index taxon for Artinskian strata throughout the Karoo Basin.Palaeo-Anthropology Scientific Trust; French Embassy in South Africa; Co-operation and Cultural Service

Quality systems in the fresh fruit export industry

The fresh fruit export industry has traditionally relied heavily on end point inspection to achieve quality. In response to several changes in international markets and concerns over the inability of end point inspection to ensure product safety and quality, many codes of practice and quality standard have been developed specifically for the food industry. This article reviews the principles and practicalities of implementation of the standards which have achieved international recognition. Producers and packers face technical challenges integrating these systems into a holistic management system while this may also present a significant entry barrier for smaller producers who lack the resources and expertise.Die varsvrugteuitvoerbedryf maak tradisioneel gebruik van eindpuntinspeksie vir die handhawing van gehalte. Twyfel oor die doeltreffendheid van hierdie vorm van inspeksie ten opsigte van veiligheid en gehalte in die konteks van internasionale markte het tot gevolg gehad dat verskeie gebruikskodes vir die voedselbedryf tot stand gekom het. Die beginsels en praktiese implementering van hierdie standaarde wat internasionale erkenning geniet, word hierin behandel. Produsente en verpakkers ondervind tegniese uitdagings oor hoe die standaarde in ’n holistiese bestuurstelsel geïntegreer kan word, gesien die problematiek van marktoetrede vir klein produsente sonder kundigheid en voldoende bronne.http://sajie.journals.ac.z

Educated mother-tongue South African English: A corpus approach

South Africa is anecdotally known for its complex system of speech varieties correlating with variables such as ethnicity, first language, class and education. These intuitions (e.g. Lass 1990) require further investigation, especially in the context of a changing South Africa where language variety plays a key role in identifying social, economic and ethnic group membership. Thus, in this research, the extent to which these variables play a role in variety is explored using a corpus approach (the nature of class and race in the corpus is discussed more fully later in the article). The corpus project, focusing primarily on accent, has been undertaken by members of the Department of English Language and Linguistics at Rhodes University in South Africa, collaborating with staff from the Department of Electrical and Electronic Engineering from Stellenbosch University, South Africa. A corpus (the first of its kind) is being compiled, comprising the speech of educated, white, mother-tongue speakers of South African English (as distinct from Afrikaans English, Indian English, and the second language (L2) varieties of English used by speakers of indigenous African languages), and data collection is well under way. This short article aims to describe the aims of the project, and the methodological approach which underpins it, as well as to highlight some of the more problematic aspects of the research

Language and learning science in South Africa

South Africa is a multilingual country with 11 official languages. However, English dominates as the language of access and power and although the Language-in- Education Policy (1997) recommends school language policies that will promote additive bilingualism and the use of learners' home languages as languages of learning and teaching, there has been little implementation of these recommendations by schools. This is despite the fact that the majority of learners do not have the necessary English language proficiency to successfully engage with the curriculum and that teachers frequently are obliged to resort to using the learners' home language to mediate understanding. This research investigates the classroom language practices of six Grade 8 science teachers, teaching science through the medium of English where they and their learners share a common home language, Xhosa. Teachers' lessons were videotaped, transcribed and analysed for the opportunities they offered learners for language development and conceptual challenge. The purpose of the research is to better understand the teachers' perceptions and problems and to be able to draw on examples of good practice, to inform teacher training and to develop a coherent bilingual approach for teaching science through the medium of English as an additional language

QUALITY SYSTEMS IN THE FRESH FRUIT EXPORT INDUSTRY

<p>ENGLISH ABSTRACT: The fresh fruit export industry has traditionally relied heavily on end point inspection to achieve quality. In response to several changes in international markets and concerns over the inability of end point inspection to ensure product safety and quality, many codes of practice and quality standard have been developed specifically for the food industry. This article reviews the principles and practicalities of implementation of the standards which have achieved international recognition. Producers and packers face technical challenges integrating these systems into a holistic management system while this may also present a significant entry barrier for smaller producers who lack the resources and expertise.</p><p>AFRIKAANSE OPSOMMING: Die varsvrugteuitvoerbedryf maak tradisioneel gebruik van eindpuntinspeksie vir die handhawing van gehalte. Twyfel oor die doeltreffendheid van hierdie vorm van inspeksie ten opsigte van veiligheid en gehalte in die konteks van internasionale markte het tot gevolg gehad dat verskeie gebruikskodes vir die voedselbedryf tot stand gekom het. Die beginsels en praktiese implementering van hierdie standaarde wat internasionale erkenning geniet, word hierin behandel. Produsente en verpakkers ondervind tegniese uitdagings oor hoe die standaarde in ’n holistiese bestuurstelsel geïntegreer kan word, gesien die problematiek van marktoetrede vir klein produsente sonder kundigheid en voldoende bronne.</p&gt

Technology integration : exploring interactive whiteboards as dialogic spaces in the foundation phase classroom

Among its many affordances, the interactive whiteboard (IWB) as a digital space for children's dialogic engagement in the Foundation Phase classroom remains largely under-exploited. This paper emanates from a study which was undertaken in an attempt to understand how teachers acquire knowledge of emerging technologies and how this shapes their classroom practices when employing technology as a pedagogic tool. The findings of this ethnographic case study show that, while teachers have become technically skilled through continuous professional teacher development (CPTD), they have also begun to reflect more rigorously on constructivism as a learning theory. Data was generated through semi-structured interviews and classroom observations with digital video recordings. Observations revealed a perceived gap in the use of the IWB as a promising space to generate reciprocal dialogue in classrooms to influence curriculum delivery and learning. This paper argues, therefore, that IWBs can become spaces for dialogic engagement to expand learners’ participation and higher order thinking skills through pedagogic strategies. Thus, there is a need to introduce Foundation Phase teachers to dialogic teaching methodologies and the potential impact thereof on learner engagement and learning

Generalized Potential Energy Finite Elements for Modeling Molecular Nanostructures

The potential energy of molecules and nanostructures is commonly calculated in the molecular mechanics formalism by superimposing bonded and nonbonded atomic energy terms, i.e. bonds between two atoms, bond angles involving three atoms, dihedral angles involving four atoms, nonbonded terms expressing the Coulomb and Lennard-Jones interactions, etc. In this work a new, generalized numerical simulation is presented for studying the mechanical behavior of three-dimensional nanostructures at the atomic scale. The energy gradient and Hessian matrix of such assemblies are usually computed numerically; a potential energy finite element model is proposed herein where these two components are expressed analytically. In particular, generalized finite elements are developed that express the interactions among atoms in a manner equivalent to that invoked in simulations performed based on the molecular dynamics method. Thus, the global tangent stiffness matrix for any nanostructure is formed as an assembly of the generalized finite elements and is directly equivalent to the Hessian matrix of the potential energy. The advantages of the proposed model are identified in terms of both accuracy and computational efficiency. In the case of popular force fields (e.g., CHARMM), the computation of the Hessian matrix by implementing the proposed method is of the same order as that of the gradient. This analysis can be used to minimize the potential energy of molecular systems under nodal loads in order to derive constitutive laws for molecular systems where the entropy and solvent effects are neglected and can be approximated as solids, such as double stranded DNA nanostructures. In this context, the sequence dependent stretch modulus for some typical base pairs step is calculated

Computational investigation of the impact of core sequence on immobile DNA four-way junction structure and dynamics

Abstract Immobile four-way junctions (4WJs) are core structural motifs employed in the design of programmed DNA assemblies. Understanding the impact of sequence on their equilibrium structure and flexibility is important to informing the design of complex DNA architectures. While core junction sequence is known to impact the preferences for the two possible isomeric states that junctions reside in, previous investigations have not quantified these preferences based on molecular-level interactions. Here, we use all-atom molecular dynamics simulations to investigate base-pair level structure and dynamics of four-way junctions, using the canonical Seeman J1 junction as a reference. Comparison of J1 with equivalent single-crossover topologies and isolated nicked duplexes reveal conformational impact of the double-crossover motif. We additionally contrast J1 with a second junction core sequence termed J24, with equal thermodynamic preference for each isomeric configuration. Analyses of the base-pair degrees of freedom for each system, free energy calculations, and reduced-coordinate sampling of the 4WJ isomers reveal the significant impact base sequence has on local structure, isomer bias, and global junction dynamics.</jats:p