Heavy Baryons with Strangeness in a Soliton Model

We present results from a chiral soliton model calculation for the spectrum of baryons with a single heavy quark (charm or bottom) and non-zero strangeness. We treat the strange components within a three flavor collective coordinate quantization of the soliton that fully accounts for light flavor symmetry breaking. Heavy baryons emerge by binding a heavy meson to the soliton. The dynamics of this heavy meson is described by the heavy quark effective theory with finite mass effects included.Comment: Ten pages, one figures, two tables, version to be published in PL

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

Monte Carlo simulation of direction sensitive antineutrino detection

Thesis (MSc (Physics))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Neutrino and antineutrino detection is a fairly new eld of experimental physics, mostly due to the small interaction cross section of these particles. Most of the detectors in use today are huge detectors consisting of kilotons of scintilator material and large arrays of photomultiplier tubes. Direction sensitive antineutrino detection has however, not been done (at the time of writing of this thesis). In order to establish the feasibility of direction sensitive antineutrino detection, a Monte Carlo code, DSANDS, was written to simulate the detection process. This code focuses on the neutron and positron (the reaction products after capture on a proton) transport through scintilator media. The results are then used to determine the original direction of the antineutrino, in the same way that data from real detectors would be used, and to compare it with the known direction. Further investigation is also carried out into the required amount of statistics for accurate results in an experimental eld where detection events are rare. Results show very good directional sensitivity of the detection method.AFRIKAANSE OPSOMMING: Neutrino en antineutrino meting is 'n relatief nuwe veld in eksperimentele sika, hoofsaaklik as gevolg van die klein interaksie deursnee van hierdie deeltjies. Die meeste hedendaagse detektors is massiewe detektors met kilotonne sintilator materiaal en groot aantalle fotovermenigvuldiger buise. Tans is rigting sensitiewe antineutrino metings egter nog nie uit gevoer nie. 'n Monte Carlo kode, DSANDS, is geskryf om die meet proses te simuleer en sodoende die uitvoerbaarheid van rigting sensitiewe antineutrino metings vas te stel. Hierdie kode fokus op die beweging van neutrone en positrone (die reaksie produkte) deur die sintilator medium. Die resultate word dan gebruik om die oorspronklike rigting van die antineutrino te bepaal, soos met data van regte detektors gedoen sou word, en te vergelyk met die bekende oorspronklike rigting van die antineutrino. Verder word daar ook gekyk na die hoeveelheid statistiek wat nodig sal wees om akkurate resultate te kry in 'n veld waar metings baie skaars is. Die resultate wys baie goeie rigting sensitiwiteit van die meet metode

Citation time windows based on citation frequency profiles of basic recognized work

In order for citation based indicators to be comparable across fields, they need to normalise for two main areas of difference among fields. The first is size differences which include factors such as number of publications and number of references per publication. The second is the time it takes for publications in a field to mature. The first area has been dealt with extensively on a publication level, while the second area has been addressed primarily on the level of fields or journals. Here we investigate the impact maturity time of different fields at the publication level and present a new way of determining an optimal, field specific citation time window. Our work also presents a way to identify 'Sleeping Beauties' and 'Genial Work'

The prevalence and genetics of Parkinson's disease in sub-Saharan Africans

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)Geneeskunde en GesondheidswetenskappeInterne Geneeskund

Investigation of the Automation of Abalone Production Control

IngenieursweseBedryfsingenieurswesePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

A clinical decision support system for needs-driven telemedicine technology development

Please help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected] En Elektroniese Ingeni

تاثير مركب بالاديوم جديد AJ-5 على خلايا سرطان الجلد

Malignant melanoma is an aggressive skin cancer and it is reported to be the most treatment-resistant human cancer. Here we describe the anti-tumour activity of a novel binuclear palladacycle complex (AJ-5) in vertical growth phase (ME1402) and metastatic (WM1158) melanoma cell lines. We show that compared to normal control cell lines, AJ-5 is more effective in inhibiting the proliferation of ME1402 and WM1158 melanoma cells with IC50values of 0.19 and 0.20 μM, respectively. Flow cytometry analyses showed that AJ-5 induced apoptosis (sub-G1 peak) which was confirmed by Annexin V-FITC/propidium iodide double-staining, nuclear fragmentation and an increase in the levels of PARP cleavage. Furthermore, AJ-5 was shown to induce both intrinsic and extrinsic apoptotic pathways as measured by PUMA, Bax and active caspases. Interestingly, AJ-5 treatment also simultaneously induced the formation of autophagosomes and led to an increase in the autophagy markers LC3II and Beclin1. Inhibition of autophagy reduced AJ-5 cytotoxicity suggesting that AJ-5 induced autophagy was a cell death and not cell survival mechanism. Moreover we show that AJ-5 induces the ATM-CHK2 DNA damage pathway and that its anti-tumour function is mediated by the p38 and ERK1/2 signalling pathways. Importantly, AJ-5 treatment efficiently reduced tumour growth in melanoma bearing mice and induced high levels of autophagy and apoptosis markers. Together these findings suggest that AJ-5 may be an effective chemotherapeutic drug in the treatment of melanoma, a highly aggressive and intractable cancer. © 2012 Elsevier B.V. All rights reserved.تاثير مركب بالاديوم جديد AJ-5 على خلايا سرطان الجل