Order of the phase transition in models of DNA thermal denaturation

We examine the behavior of a model which describes the melting of double-stranded DNA chains. The model, with displacement-dependent stiffness constants and a Morse on-site potential, is analyzed numerically; depending on the stiffness parameter, it is shown to have either (i) a second-order transition with "nu_perpendicular" = - beta = 1, "nu_parallel" = gamma/2 = 2 (characteristic of short range attractive part of the Morse potential) or (ii) a first-order transition with finite melting entropy, discontinuous fraction of bound pairs, divergent correlation lengths, and critical exponents "nu_perpendicular" = - beta = 1/2, "nu_parallel" = gamma/2 = 1.Comment: 4 pages of Latex, including 4 Postscript figures. To be published in Phys. Rev. Let

Die psigologie van spelmoeilikhede : 'n literatuurstudie

Proefskrif (M. Ed.) -- Universiteit van Stellenbosch, 1940.Full text to be digitised and attached to bibliographic record

The history of the controlled marketing of South African deciduous fruit, 1951-1980

Thesis (D. Phil.) -- University of Stellenbosch, 1987.Full text to be digitised and attached to bibliographic record

A novel binuclear palladacycle complex inhibits melanoma growth <i>in vitro</i> and <i>in vivo</i> through apoptosis and autophagy

Please help populate SUNScholar with the full text of SU research output. Also - should you need this item urgently, please send us the details and we will try to get hold of the full text as quick possible. E-mail to [email protected]. Thank you.Journal Articles (subsidised)NatuurwetenskappeChemie & Polimeerwetenska

Impact of the introduction of a colposcopy service in a rural South African sub-district on uptake of colposcopy

CITATION: Blanckenberg, N. D. et al. 2013. Impact of the introduction of a colposcopy service in a rural South African sub-district on uptake of colposcopy. South African Journal of Obstetrics and Gynaecology, 19(3):81-85, doi:10.7196/sajog.388.The original publication is available at http://www.sajog.org.zaObjectives. To describe the establishment of a colposcopy service at a district hospital in a rural sub-district of the Western Cape, South Africa, and assess its impact on colposcopy uptake. Design. A retrospective double-group cohort study using a laboratory database of cervical cytology results, clinical records and colposcopy clinic registers. Setting. The Overstrand sub-district, where 80 000 people are served by seven clinics and a district hospital in Hermanus, 120 km from its referral hospitals in Cape Town and Worcester. A colposcopy service was established at Hermanus Hospital in 2008. Subjects. All women in the sub-district who required colposcopy on the basis of cervical smears done in 2007 and 2009. Outcome measures. Numbers of women booked for colposcopy at distant referral hospitals in 2007 and at the district hospital in 2009, the proportions who attended colposcopy, the time from cervical smear to colposcopy, and comparison between the two years. Results. Uptake of colposcopy booked at distant referral hospitals was 67% in 2007. Uptake improved by 18% to 79% for the district hospital colposcopy service in 2009 (p=0.06). When patients from an area with no public transport to the district hospital were excluded from analysis, the improvement was more marked at 22% (p=0.02). The delay from cervical smear to colposcopy improved significantly from 170 to 141 days (p=0.02). Conclusion. Establishment of a colposcopy service in a rural sub-district increased uptake of colposcopy and decreased the delay from cervical smear to colposcopy. The service removed 202 booked patients in one year from the colposcopy load of the referral hospitals.http://www.sajog.org.za/index.php/SAJOG/article/view/388Publisher's versio

تاثير مركب باليديوم جديد على السرطان

A series of novel mononuclear 1,3,5-triaza-7-phosphaadamantane (PTA)-based palladacycles were prepared by cleaving μ-Cl binuclear orthopalladated dimers of substituted benzylidene-2,6-diisopropylphenylamines. All complexes were fully characterized using IR and NMR spectroscopy, mass spectrometry as well as elemental analysis. In-vitro evaluation of the complexes as anti-cancer agents against the breast-cancer cell lines MCF7 and MDA-MB 231 as well the melanoma cell line ME1402 shows that four of the five complexes tested are active. These palladacycles exhibit their cytotoxicity by inducing DNA damage which subsequently triggers apoptosis. DNA binding studies using electrophoresis and spectroscopic techniques, such as UV-Vis and circular dichroism spectroscopy, confirms that the palladacycle, C2 definitely interacts with DNA. Results from these DNA binding experiments seem to rule out co-valent and intercalative binding, pointing rather to a non-covalent interaction, with electrostatic binding being the most likely possibility. It is envisioned that this would probably involve a hydrolysed or solvated derivative of C2.تم تصنيع واختبار عقار جديد مشتق من novel mononuclear 1,3,5-triaza-7-phosphaadamantane (PTA)-based palladacycles ضد مجموعة من الخلايا السرطانية. المركب اثبت فعالية باحداث الموت للخلايا

Patient-Control Association Study of the Leucine-Rich Repeat Kinase 2 (LRRK2) Gene in South African Parkinson's Disease Patients

The leucine-rich repeat kinase 2 (LRRK2) gene is of interest to Parkinson's disease (PD) as it has been implicated in both familial and sporadic forms of the disorder.1 PD-susceptibility alleles in LRRK2 appear to be ethnic-specific with G2385R,2 R1628P3 and A419V4 identified in Asian populations, whereas M1646T is found in Caucasians.4 A haplotype protecting against development of PD is present in Chinese (N551K-R1398H)5 and Caucasians (N551K-R1398H-K1423K).4 Further studies are necessary to investigate the contribution of LRRK2 to PD-susceptibility in various populations worldwide.Department of HE and Training approved lis

High frequency of rapid immunological progression in African infants infected in the era of perinatal HIV prophylaxis.

OBJECTIVES: To determine the natural history of HIV infection following peripartum single-dose nevirapine (sd-NVP) prophylaxis in a resource-limited country, and to assess implications for antiretroviral therapy (ART) roll-out programmes. METHODS: Infants of HIV-infected mothers in KwaZulu-Natal, South Africa, were tested on days 1 and 28 to detect intrauterine (IU) and intrapartum (IP) infection. Infant follow-up included monthly viral load and CD4 cell measurement. ART was initiated at infant CD4 cell% &lt; or = 20%. RESULTS: In 740 infants born to 719 HIV-infected women, mother-to-child transmission (MTCT) was 10.3% (69% IU, 31% IP). Median viral load was higher in mothers of infants infected IP than IU (279 000 versus 86 600 copies/ml; P = 0.039) and lower in mothers of uninfected infants (median 26 750 copies/ml; P &lt; 0.001). Peak viraemia was higher in infants infected IP than IU (5 160 000 versus 984 000 copies/ml; P &lt; 0.001). Median viral load at birth in IU-infected infants (155 000 copies/ml) fell 1.4 log to 6510 copies/ml by day 5 and was beneath the detection limit using dried blood spot analysis in 38% of infants. CD4 cell% declined rapidly, to &lt; or = 20% in 70% and &lt; or = 25% in 85% [current World Health Organization (WHO) criteria for initiating ART] of infants by 6 months. CONCLUSIONS: MTCT was reduced by sd-NVP through an effect on IP transmission. Where MTCT occurred despite NVP, two-thirds of transmissions arose IU; IP-infected babies were born to mothers with very high viral load. Disease progression was particularly rapid, 85% infants meeting WHO criteria for ART within 6 months. These findings argue for more effective MTCT-prevention programmes in resource-limited countries

Limited Diversity among Human Isolates of Bartonella henselae

A study of 59 isolates of Bartonella henselae reveals relatively limited diversity among those of human origin (n = 28). Either of two distinct alleles of both gltA and 16S ribosomal DNA (rDNA) was found in all isolates, with a high level of congruity between 16S and gltA inheritance among proven human pathogens. Human isolates from all over Eastern Australia were most commonly 16S rDNA (Bergmans) type I, with the same gltA allele as the type strain (Houston-1). Comparable feline isolates were more commonly 16S type II, with less congruity of inheritance between 16S and gltA alleles. Previously described arbitrarily primed PCR and EagI-HhaI infrequent restriction site PCR fingerprinting techniques separated Bartonella species effectively but lacked discriminating power within B. henselae. Examination of the 16-23S intergenic spacer region revealed for several strains several point mutations as well as a repeat sequence of unknown significance which is readily detected by HaeIII restriction fragment length polymorphism analysis. The bacteriophage-associated papA gene was present in all isolates. Enterobacterial repetitive intergenic consensus PCR proved to be a useful and robust typing tool and clearly separated human isolates (including imported strains) from the majority of feline isolates. Our data are consistent with published evidence and with previous suggestions of intragenomic rearrangements in the type strain and suggest that human isolates come from a limited subset of B. henselae strains. They strengthen arguments for careful exploration of genotype-phenotype relationships and for the development of a multilocus enzyme electrophoresis and multilocus sequence typing-based approach to the phylogeny of B. henselae