A comparative study between the determination of dry matter digestibility in vitro and in vivo

(South African J of Animal Science, 2000, 30, Supplement 1: 47-48

Gamma ray production cross sections in proton induced reactions on natural Mg, Si and Fe targets over the proton energy range 30 up to 66 MeV

Gamma-ray excitation functions have been measured for 30, 42, 54 and 66 MeV proton beams accelerated onto C + O (Mylar), Mg, Si, and Fe targets of astrophysical interest at the separate-sector cyclotron of iThemba LABS in Somerset West (Cape Town, South Africa). A large solid angle, high energy resolution detection system of the Eurogam type was used to record Gamma-ray energy spectra. Derived preliminary results of Gamma-ray line production cross sections for the Mg, Si and Fe target nuclei are reported and discussed. The current cross section data for known, intense Gamma-ray lines from these nuclei consistently extend to higher proton energies previous experimental data measured up to Ep ~ 25 MeV at the Orsay and Washington tandem accelerators. Data for new Gamma-ray lines observed for the first time in this work are also reported.Comment: 11 pages, 6 figures. IOP Institute of Physics Conference Nuclear Physics in Astrophysics VII, 28th EPF Nuclear Physics Divisional Conference, May 18-22 2015, York, U

Prevalence of dry eye amongst black and Indian university students aged 18–30 years

Background: The overall prevalence of dry eye in South Africa seems to be increasing. University students work under conditions predisposing them to dry eye, which may affect some tasks. The predominant race groups at the University of KwaZulu-Natal (UKZN) are black and Indian, which suggested a study in this student population to assist the diagnosis and management of such subjects. Aim and setting: To compare the prevalence of dry eye amongst black and Indian students at the UKZN’s Westville campus. Methods: One hundred participants, equally divided by gender and race, between 18 and 30 years old were enrolled. Dry eye symptoms were investigated by the ocular surface disease index (OSDI), tear thinning time (TTT), tear breakup time (TBUT) and Schirmer’s 2 in that sequence on both eyes of each participant. Results: The OSDI revealed that 41% of participants had some dry eye symptoms whilst 59% had no symptoms. Clinical testing showed that 81% of participants had dry eye. Half of the black participants had dry eye symptoms and 82% had clinical signs of dry eye. Of the 50 Indian participants, 32% had dry eye symptoms and 80% had clinical signs. Of the 50 male participants, 34% were symptomatic and 86% had clinical signs. Of the 50 female participants, 48% had dry eye symptoms and 76% had clinical signs. Participants were asymptomatic even in the presence of clinical dry eye signs. Conclusion: For both races and genders, clinical signs of dry eye were more common than symptoms. Black participants were more likely to report symptoms than Indians, and more women than men reported having symptoms. Male participants were more likely than female to have clinical signs of dry eye

First social impact bond for the SAMRC: A novel financing strategy to address the health and social challenges facing adolescent girls and young women in South Africa

A social impact bond (SIB) is an innovative financing mechanism to attract investors to social programmes traditionally funded by governments. In this article, in celebration of the 50th anniversary of the South African Medical Research Council (SAMRC), the authors describe the SAMRC’s first foray into this new world of financing through a SIB to improve the health and quality of life of adolescent girls and young women (AGYW). The AGYW SIB is in its preparatory phase and is scheduled for implementation in 2020. The authors describe the mechanism, including financial flows and the process of customising the SIB to meet the needs of AGYW, focusing on HIV prevention and treatment and the prevention and management of unintended pregnancies in schoolgoing AGYW. The authors outline an approach to designing the package of interventions, the metrics associated with such a programme and the business model. It is hypothesised that the proposed approach will lead to an improvement in programmatic outcomes, monitoring and evaluation tools and cost-effectiveness, and will develop key learning data for the future use of SIBs in health service delivery

Statistical gamma-ray decay studies at iThemba LABS

Abstract. A program to study the γ -ray decay from the region of high-level density has been established at iThemba LABS, where a high-resolution gamma-ray detector array is used in conjunction with silicon particle-telescopes. Results from two recent projects are presented: 1) The 74Ge(α, α γ ) reaction was used to investigate the Pygmy Dipole Resonance. The results were compared to (γ,γ ) data and indicate that the dipole states split into mixed isospin and relatively pure isovector excitations. 2) Data from the 95Mo(d,p) reaction were used to develop a novel method for the determination of spins for low-lying discrete levels utilizing statistical γ -ray decay in the vicinity of the neutron separation energy. These results provide insight into the competition of (γ ,n) and (γ,γ ) reactions and highlights the need to correct for angular momentum barrier effect

Nuclear Level Density and γ\gamma-ray Strength Function of 67Ni^{67}\mathrm{Ni} and the impact on the i-process

Proton-$\gamma$ coincidences from $(\mathrm{d},\mathrm{p})$ reactions between a $^{66}\mathrm{Ni}$ beam and a deuterated polyethylene target have been analyzed with the inverse Oslo method to find the nuclear level density (NLD) and $\gamma$-ray strength function ($\gamma$SF) of $^{67}\mathrm{Ni}$. The $^{66}\mathrm{Ni}(\mathrm{n},\gamma)$ capture cross section has been calculated using the Hauser-Feshbach model in TALYS using the measured NLD and $\gamma$SF as constraints. We confirm that $^{66}\mathrm{Ni}(\mathrm{n},\gamma)$ acts as a bottleneck when relying on one-zone nucleosynthesis calculations. However, we find that the impact of this reaction is strongly damped in multi-zone low-metallicity AGB stellar models experiencing i-process nucleosynthesis.Comment: Submitted to Phys. Rev.

Octupole correlations in the structure of O2 bands in the N=88 nuclei150Sm Gd

Knowledge of the exact microscopic structure of the 01 + ground state and first excited 02 + state in 150Sm is required to understand the branching of double β decay to these states from 150Nd. The detailed spectroscopy of 150Sm and 152Gd has been studied using (α,xn) reactions and the γ -ray arrays AFRODITE and JUROGAM II. Consistently strong E1 transitions are observed between the excited Kπ = 02 + bands and the lowest negative parity bands in both nuclei. These results are discussed in terms of the possible permanent octupole deformation in the first excited Kπ = 02 + band and also in terms of the “tidal wave” model of Frauendorf.Web of Scienc

Assessing adherence in the CAPRISA 004 tenofovir gel HIV prevention trial: results of a nested case–control study.

CAPRISA, 2014.Abstract available in pdf