100 research outputs found
Evidence
The court noted in S v Mbelo 2003 (1) SACR 84 (NCD) that `[w]here the age of either an accused or a complainant is material to either the offence or to sentence, hearsay evidence thereof is admissible' (at para 8). (See also S v Moeketsi 1976 (4) SA 838 (O); S v Magqabudi 1983 (4) SA 54 (Tk). Majiedt J also held that a baptismal certificate was not sufficient proof of age. However, the court held that formal admissions made by the accused's legal representative in the pleadings were binding and sufficient proof of the ages in question
Professional incompetence voluntariness and the right to a fair trial
It is obvious that the right to legal representation, guaranteed in s 35 of the Constitution of the Republic of South Africa must include competent legal representation. The right to legal representation is traditionally viewed as a pre-requisite for the protection of the privilege against self-incrimination.1 If this line of reasoning is pursued it follows that competent legal representation is required to uphold the privilege against self-incrimination. But the following questions arise: how does a court determine incompetence and when will incompetence render a trial unfair
The Law of evidence
The Supreme Court of Appeal dealt with the withdrawal of an admission in civil proceedings in Saayman v Road Accident Fund 2011 (1) SA 106 (SCA). The court (para [12]) held that a concession made during the course of counselβs address did not amount to a formal admission. Consequently, it was not necessary for an application for a formal withdrawal of the statement to be made. It was possible for the concession be withdrawn at any time during the trial in the absence of prejudice to the opposing party. Heher JA (Leach JA and Majiedt AJA concurring), agreeing with the majority judgment of Bosielo JA, gave a separate judgment providing additional grounds and it is in this judgment that the court expands on the characteristics of an admission. The first hurdle to overcome in following this aspect of the judgment is to determine whether the court views the arguments presented as pertaining to informal or formal admissions. The court explicitly characterizes the relevant statements as informal admissions as they were not recorded as admissions by the court. In doing so the judges refer to section 5 of the Civil Proceedings Evidence Act 25 of 1965, which is somewhat confusing, as section 5 has nothing to say on the matter. (This is perhaps due to the fact that DT Zeffertt, AP Paizes and A St Q Skeen (The South African Law of Evidence (2003) 784) mistakenly refer to section 5 when they actually mean section 15.
An investigation of advanced oxidation processes in water treatment.
Thesis (Ph.D.)-University of Natal, Durban, 2001.The deteriorating water quality in South Africa and changing legislation requiring the industrial
implementation of waste minimisation and pollution prevention technologies has highlighted the need for
the investigation of new effluent treatment technologies such as advanced oxidation processes.
This investigation details the evaluation of ultrasound, an emerging advanced oxidation process, to degrade
organic compounds during water treatment. The objectives of the investigation included the design of a
suitable ultrasonic laboratory reactor to investigate ultrasound chemistry and the sub-processes occurring
during sonication. Atrazine was used as a model compound to compare the performance of ultrasound with
that of ozone and hydrogen peroxide, already established advanced oxidation processes. Recommendations
have also been made for the scale-up of ultrasonic processes.
A 500 mL ultrasonic cell containing an ultrasonic horn as an energy source was designed and constructed.
The measurement of hydrogen peroxide concentration was used as a tool to indicate the process conditions
under which the formation of free radical reactions during sonication are enhanced. These include the
application of oxygen and air sparging or the addition of a commercial source of hydrogen peroxide. It was
found that oxygen sparging and a high acoustic power input should be used in ultrasonic processes with a
short retention time, and conversely, that air sparging and a lower acoustic energy source should be used in
processes with a long retention time. A flow loop system should be considered to maximise oxidation both
within and beyond the sonicated zone, gas sparging should only occur within the sonication zone else the
degradation of hydrogen peroxide is encouraged. Ultrasound is most effectively applied in water treatment
as a pretreatment stage in combination with other technologies and not as a stand-alone process.
Atrazine was used. as a model compound to compare the performance of ultrasound with ozone because of
its persistence in the environment and resistance to degradation. Atrazine was degraded during sonication
and ozonation. degradation increased wim the addition of hydrogen peroxide. Ozone decomposition (and
hence free radical reactions) was enhanced when ozone was combined with ultrasound or hydrogen
peroxide. Enhanced ozone decomposition during ozonation combined with sonication is due to the
conditions (high temperatures and pressures) as well as the free radical reactions occurring within the
collapsing cavitation bubbles and at the gas-liquid interface. The enhancing effect of combining ultrasound
with ozone was greatest at the low ozone concentrations typically applied during water treatment.
Atrazine degradation during sonication and ozonation is predominantly due to the reaction with hydroxyl
radicals. Atrazine degradation products identified using gas chromatography and mass spectrometry were
deethylatrazine. hydroxyatrazine and deethyldeisopropylatrazine (tentatively identified)
Synthesis and evaluation of bis(imino)anthracene derivatives as G-quadruplex ligands
The synthesis of a small number of bis(imino)anthracene derivatives is reported. They were evaluated via NMR for binding efficacy to the G-quadruplex-forming oligonucleotide sequence (TTGGGTT) and show activity against the HeLa cancer cell line. These novel ligands are compared to previously synthesised G-quadruplex ligands that target telomeres and oncogenes
Phytochemical investigations of three Rhodocodon (Hyacinthaceae Sensu APG II) species
The genus Rhodocodon (Hyacinthaceae sensu APG II) is endemic to Madagascar and its phytochemistry has not been described previously. The phytochemistry of three species in this genus has been investigated and eight compounds, including three bufadienolides (compounds 1, 4, and 5), a norlignan (2), and four homoisoflavonoids (compounds 3 and 6-8) have been isolated and identified. Compounds 1-3 and 6-8 have not been described previously. The COX-2 inhibitory activity of compound 6 and compound 7 acetate (compound 7A) were investigated on isolated colorectal cancer cells. Compounds 6 and 7A inhibited COX-2 by 10% and 8%, respectively, at a concentration of 12.5 M compared to 12% for 1 mM aspirin (the positive control)
Antiangiogenic activity and cytotoxicity of triterpenoids and homoisoflavonoids from 'Massonia pustulata' and 'Massonia bifolia'
The Hyacinthaceae family (sensu APGII) with approximately 900 species in around 70 genera, plays a significant role in traditional medicine in Africa as well as across Europe and the Middle and Far East. The dichloromethane extract of the bulbs of Massonia pustulata (Hyacinthaceae sensu APGII) yielded two known homoisoflavonoids, (R)-5-hydroxy-3-(4-hydroxybenzyl)-7-methoxy-4-chromanone 1 and 5-hydroxy-3-(4-hydroxybenzyl)-7-methoxy-4-chromone 2 and four spirocyclic nortriterpenoids, eucosterol 3, 28-hydroxyeucosterol 4 and two previously unreported triterpenoid derivatives, (17S,23S)-17Ξ±,23-epoxy-3Ξ²,22Ξ²,29-trihydroxylanost-8-en-27,23-olide 5 and (17S, 23S)-17Ξ±,23-epoxy-28,29-dihydroxylanost-8-en-3-on-27,23-olide 6. Compounds 1, 2, 3, and 5 were assessed for cytotoxicity against CaCo-2 cells using a neutral red uptake assay. Compounds 1, 2 and 5 reduced cell viability by 70% at concentrations of 30, 100 and 100 ΞΌM respectively. Massonia bifolia yielded three known homoisoflavonoids, (R)-(4β-hydroxy)-5-hydroxy-7-methoxy-4-chromanone 1, (R)-(4β-hydroxy)-5,7-dihydroxy-4-chromanone 7 and (R)-(3β-hydroxy-4β-methoxy)-5,7-dihydroxy-4-chromanone 9, two previously unreported homoisoflavonoids, (E)-3-benzylidene-(3β,4β-dihydroxy)-5-hydroxy-7-methoxy-4-chromanone 8 and (R)-(3β,4β-dihydroxy)-5-hydroxy-7-methoxy-4-chromanone 10, and a spirocyclic nortriterpenoid, 15-deoxoeucosterol 11. Compounds 1, 1Ac, 7, 8, 9 and 10 were screened for antiangiogenic activity against human retinal microvascular endothelial cells. Some compounds showed dose-dependent antiproliferative activity and blocked endothelial tube formation, suggestive of antiangiogenic activity
Lipid Lowering Activity of Anthocephalus indicus Root in Hyperlipidemic Rats
The lipid lowering activity of Anthocephalus indicus (family Rubiaceae; Hindi name Kadamba) root extract has been studied in triton WR-1339 induced hyperlipidemia in rats. In this model, feeding with root extract (500 mg kgβ1 b.w.) lowered plasma lipids and reactivated post-heparin lipolytic activity in hyperlipidemic rats. Furthermore, the root extract (50β500 ΞΌM) inhibited the generation of superoxide anions and hydroxyl radicals, in both enzymic and non-enzymic systems, in vitro. The results of the present study demonstrated both lipid lowering and antioxidant activities in root extract of A. indicus, which could help prevention of hyperlipidemia and related diseases
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