182 research outputs found
LOOKING INSIDE VOTIVE CREATURES: COMPUTED TOMOGRAPHY (CT) SCANNING OF ANCIENT EGYPTIAN MUMMIFIED ANIMALS IN IZIKO MUSEUMS OF SOUTH AFRICA: A PRELIMINARY REPORT
The ancient Egyptians mummified many more animals than humans.
The study of ancient Egyptian animal mummies is varied and
extensive. Currently new methodologies and modern technology are
being used to unlock the secrets of animal mummies. Recently five
animal mummies housed in the Egyptian collection of Iziko
Museums of South Africa in Cape Town were scanned using a state
of the art computed tomography (CT) scanner at Stellenbosch
University. Preliminary results revealed two complete bird skeletons,
a claw, a fake and the partial skeleton of what appears to be a cat
Legislation governing pluripotent stem cells in South Africa
One of the most exciting areas of medical research involves the use of stem cells for the treatment of patients with a variety of diseases and for tissue repair. Although stem cell research is accelerating rapidly in many countries, it has in the past been limited in South Africa (SA); very little has been done in this country to explore the great potential offered by stem cells to address the high disease burden. Stem cell therapy has however been practised for many years, in SA and worldwide, in the form of haematopoietic stem cell transplantation, mainly for haematological malignancies.
From a therapeutic perspective, two types of stem cells can be defined: pluripotent stem cells and adult stem cells. Pluripotent cells derived from the inner cell mass of blastocysts (either from in vitro fertilisation or following somatic cell nuclear transfer) are called embryonic stem (ES) cells, while those derived by reprogramming adult cells are called induced pluripotent stem (iPS) cells. Adult stem cells include haematopoietic, mesenchymal and neural stem cells.
The purpose of this article is to critically examine the SA legislation with regard to elements that impact on pluripotent stem cell research and the use of pluripotent stem cells for therapeutic purposes. This includes (but is not limited to) legislation from the National Health Act (Chapter 8 in particular) and its regulations, and deals with matters related to research on embryos in the stem cell context, somatic cell nuclear transfer, reproductive and therapeutic cloning and the generation and therapeutic use of iPS and ES cells.The Medical Research Council of South Africa in terms of the MRC’s Flagships Awards Project SAMRC-RFA-UFSP-01-2013/STEM CELLShttp://www.sajbl.org.zaam201
Legislation governing pluripotent stem cells in South Africa
One of the most exciting areas of medical research involves the use of stem cells for the treatment of patients with a variety of diseases and for tissue repair. Although stem cell research is accelerating rapidly in many countries, it has in the past been limited in South Africa (SA); very little has been done in this country to explore the great potential offered by stem cells to address the high disease burden. Stem cell therapy has however been practised for many years, in SA and worldwide, in the form of haematopoietic stem cell transplantation, mainly for haematological malignancies.
From a therapeutic perspective, two types of stem cells can be defined: pluripotent stem cells and adult stem cells. Pluripotent cells derived from the inner cell mass of blastocysts (either from in vitro fertilisation or following somatic cell nuclear transfer) are called embryonic stem (ES) cells, while those derived by reprogramming adult cells are called induced pluripotent stem (iPS) cells. Adult stem cells include haematopoietic, mesenchymal and neural stem cells.
The purpose of this article is to critically examine the SA legislation with regard to elements that impact on pluripotent stem cell research and the use of pluripotent stem cells for therapeutic purposes. This includes (but is not limited to) legislation from the National Health Act (Chapter 8 in particular) and its regulations, and deals with matters related to research on embryos in the stem cell context, somatic cell nuclear transfer, reproductive and therapeutic cloning and the generation and therapeutic use of iPS and ES cells.The Medical Research Council of South Africa in terms of the MRC’s Flagships Awards Project SAMRC-RFA-UFSP-01-2013/STEM CELLShttp://www.sajbl.org.zaam201
Concern level assessment: building domain knowledge into a visual system to support network-security situation awareness
Information officers and network administrators require tools to help them achieve situation awareness about potential network threats. We describe a response to mini-challenge 1 of the 2012 IEEE VAST challenge in which we developed a visual analytic solution to a network security situation awareness problem. To support conceptual design, we conducted a series of knowledge elicitation sessions with domain experts. These provided an understanding of the information they needed to make situation awareness judgements as well as a characterisation of those judgements in the form of production rules which define a parameter we called the ‘Concern Level Assessment’ (CLA). The CLA was used to provide heuristic guidance within a visual analytic system called MSIEVE. An analysis of VAST challenge assessment sessions using M-SIEVE provides some evidence that intelligent heuristics like this can provide useful guidance without unduly dominating interaction and understanding
M-Sieve: a visualisation tool for supporting network security analysts
The Middlesex Spatial Interactive Visualisation Environment (M-Sieve) is a spatiotemporal visual analytics tool for exploring computer network activity. M-Sieve allows the user to filter and visualize data through facets to explore and find patterns. To help guide exploration, we developed a set of rules which are used to derive a variable we call the ‘Concern Level Assessment’ (CLA). The CLA is based on attributes of nodes on the network. The rules were developed by eliciting inferences from network security domain experts. The combination of M-Sieve and the CLA allowed us to address the problem presented by the VAST 2012 Competition - Mini Challenge 1
Transcriptome characterization of the South African abalone Haliotis midae using sequencing-by-synthesis
<p>Abstract</p> <p>Background</p> <p>Worldwide, the genus <it>Haliotis </it>is represented by 56 extant species and several of these are commercially cultured. Among the six abalone species found in South Africa, <it>Haliotis midae </it>is the only aquacultured species. Despite its economic importance, genomic sequence resources for <it>H. midae</it>, and for abalone in general, are still scarce. Next generation sequencing technologies provide a fast and efficient tool to generate large sequence collections that can be used to characterize the transcriptome and identify expressed genes associated with economically important traits like growth and disease resistance.</p> <p>Results</p> <p>More than 25 million short reads generated by the Illumina Genome Analyzer were <it>de novo </it>assembled in 22,761 contigs with an average size of 260 bp. With a stringent <it>E</it>-value threshold of 10<sup>-10</sup>, 3,841 contigs (16.8%) had a BLAST homologous match against the Genbank non-redundant (NR) protein database. Most of these sequences were annotated using the gene ontology (GO) and eukaryotic orthologous groups of proteins (KOG) databases and assigned to various functional categories. According to annotation results, many gene families involved in immune response were identified. Thousands of simple sequence repeats (SSR) and single nucleotide polymorphisms (SNP) were detected. Setting stringent parameters to ensure a high probability of amplification, 420 primer pairs in 181 contigs containing SSR loci were designed.</p> <p>Conclusion</p> <p>This data represents the most comprehensive genomic resource for the South African abalone <it>H. midae </it>to date. The amount of assembled sequences demonstrated the utility of the Illumina sequencing technology in the transcriptome characterization of a non-model species. It allowed the development of several markers and the identification of promising candidate genes for future studies on population and functional genomics in <it>H. midae </it>and in other abalone species.</p
Free radicals produced by the oxidation of gallic acid: An electron paramagnetic resonance study
<p>Abstract</p> <p>Background</p> <p>Gallic acid (3,4,5-trihydroxybenzoic acid) is found in a wide variety of plants; it is extensively used in tanning, ink dyes, as well as in the manufacturing of paper. The gallate moiety is a key component of many functional phytochemicals. In this work electron paramagnetic spectroscopy (EPR) was used to detect the free radicals generated by the air-oxidation of gallic acid.</p> <p>Results</p> <p>We found that gallic acid produces two different radicals as a function of pH. In the pH range between 7-10, the spectrum of the gallate free radical is a doublet of triplets (a<sup>H </sup>= 1.00 G, a<sup>H </sup>= 0.23 G, a<sup>H </sup>= 0.28 G). This is consistent with three hydrogens providing hyperfine splitting. However, in a more alkaline environment, pH >10, the hyperfine splitting pattern transforms into a 1:2:1 pattern (a<sup>H </sup>(2) = 1.07 G). Using D<sub>2</sub>O as a solvent, we demonstrate that the third hydrogen (<it>i.e</it>. a<sup>H </sup>= 0.28 G) at lower pH is a slowly exchanging hydron, participating in hydrogen bonding with two oxygens in <it>ortho </it>position on the gallate ring. The p<it>K</it><sub>a </sub>of this proton has been determined to be 10.</p> <p>Conclusions</p> <p>This simple and novel approach permitted the understanding of the prototropic equilibrium of the semiquinone radicals generated by gallic acid, a ubiquitous compound, allowing new insights into its oxidation and subsequent reactions.</p
Response of Cyclopia subternata to drought stress � assessment of leaf composition, proteomics and product quality
Honeybush tea is made from the fynbos plant Cyclopia subternata, which is unique to South Africa. Cultivation takes place in its natural environment, which has a Mediterranean climate with dry summers and wet
winters. During the summer, the plant is vulnerable to drought, an abiotic stress factor that is likely to affect
its development and yield. This study investigated the effect of drought stress for a short duration on the
leaf, as well as the quality of the herbal tea. Protein expression in the leaf was measured to gain insight into
possible mechanisms used by the plant to cope with drought stress conditions. Fifteen-month-old C. subternata plants were subjected to three water treatments (control, moderately-stressed (MS), and severelystressed (SS)) for ten days. Leaves were sampled at regular intervals throughout the treatment period to
determine their relative water content (RWC). Leaves were also sampled on the 11th day for untargeted and
targeted chemical composition and protein expression analyses. The remaining leaves and stems were processed to obtain the herbal tea. Descriptive sensory analysis of the herbal tea was performed to determine
whether drought stress affected product quality. RWC was substantially higher (p < 0.05) in the control
plants (100%) than in the MS and SS treated plants (83�90% and 47%, respectively). Untargeted analysis
revealed that drought stress considerably altered leaf chemical composition. According to targeted analysis,
the proline content of SS treated plants increased more than 40-fold when compared to the control, however,
the treatments had no effect on the total carbohydrate and major phenolic compound content of the leaves,
nor on the sensory quality of the herbal tea. Differences in the expression of 27 proteins, 24 of which were
identified using proteomic analysis, were observed. During drought stress, 17 of these proteins increased,
whereas seven decreased. Thirteen of the 24 identified proteins produced statistically significant results
based on their Byonic scores. The findings laid the foundation for future research into the functions of
drought response genes in Cyclopia species, as well as helping with the identification of stress-tolerant honeybush genotypes
Efficacy of tissue brushing as measured by the prosthodontic tissue index
This study was conducted to determine the efficacy of brushing the oral mucosa supporting complete dentures with a soft brush to see if this treatment would reduce inflammation. The oral mucosa health status of 60 patients was monitored for 120 days using the PTI to measure inflammation. For comparison the patients were divided into two groups, and every effort was made to balance the groups for those variables that may effect inflammation. The patients were also compared with themselves. The experiment consisted of three phases; Phase 1 established baseline data, and Phases 2 and 3 were information-gathering sessions. Each patient received brushing instructions at the start of the brushing test period and additional brushing instruction during a reinforcement session after 30 days. Tissue brushing did reduce the inflammation index of the oral mucosa examined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74782/1/j.1754-4505.1984.tb00150.x.pd
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