Aspects of the early life history and a per-recruit assessment of white stumpnose Rhabdosargus globiceps (Pisces: Sparidae) in Saldanha Bay with recommendations for future research and monitoring

This study focuses on several aspects of the life history of R. globiceps, and includes a study of juvenile habitat, a hatch date analysis, methods to increase precision of age estimates obtained from reading otoliths and a per-recruit assessment

An examination into the role of a peer academic online mentoring programme during Emergency Remote Teaching at a South African residential university

For residential universities, the COVID-19 pandemic in the 2020 academic year necessitated the suspension of in-person lectures and a swift transition of classes and other in-person activities to emergency remote teaching (ERT). This included the academic module mentoring programme, cognisant of the potential challenges experienced by first-year students during a period of ERT. The role of an in-person module mentoring programme before ERT was only to provide academic support to first-year students within an introductory financial accounting module to promote student success. This study investigated the role of an academic online mentoring programme for students in an introductory financial accounting module during ERT. A web-based survey was conducted to source the perceptions of both mentors and mentees who participated in an introductory module academic mentoring programme both before and during ERT to analyse whether the role of the academic module mentoring programme had shifted beyond that of academic support in an ERT environment. While academic support remained at the forefront as the main perceived benefit of the online mentoring programme, with the transition to ERT, the findings of this study illustrate an altering role that is more inclusive of additional psychological and peer support and engagement perceived benefits for first-year students who participated in an academic mentoring programme for students in an introductory financial accounting module during a period of ERT. Understanding student perceptions of the value derived for first-year students from an academic online mentoring programme is important in understanding first-year student needs and to provide relevant and applicable training to first-year students to promote student success during ERT. The findings of this study provide insight to institutions and in considering the addition of academic interventions such as offering academic online mentoring programmes during ERT and highlight the perceived value-add from both a mentor and mentee perspective

Characterization of silicon nitride thin films deposited by hot-wire CVD at low gas flow rates

We examined the chemical, structural, mechanical and optical properties of amorphous hydrogenatedsilicon nitride thin films deposited by hot-wire chemical vapour deposition using SiH4, NH3and H2gases at total flow rates below 33 sccm. Time of flight secondary ion mass spectroscopy reveal that thefilm surfaces consist of predominantly Si with hydrogenated SixNyOzspecies. Energy dispersive X-rayspectroscopy and X-ray photoelectron spectroscopy corroborate on the N/Si ratio. Electron energy lossspectroscopy discloses that the thickness of the nitrogen rich oxidized interface between the SiNxfilmsand the c-Si substrate decrease with an enhancing NH3flow rate. By varying the NH3flow rate, denseSiNxfilms can be realized with hydrogen content between 16 and 9 at.%, a refractive index between 3.5and 1.9 and optical band gap ranging from 2 to 4.5 eV. The SiNxfilm stress is compressive for N/Si 0.55. Mechanisms relating the HWCVD conditions and the film structure andproperties are proposed.Web of Scienc

The winner takes it all : outperformance drives subsequent flows in South African unit trust funds

The relationship between unit trust (mutual fund) performance and subsequent investment flows into and out of funds has been the focus of many international studies. Emerging markets, which are characterised by higher risk, weaker institutions, volatile economies and fewer participants, provide an attractive opportunity to examine the flow-performance problem in the context of higher arbitrage costs. This study builds on the findings in the literature of the flowperformance relationship and aims to examine in more detail, and to quantify, the inflow into funds which outperform. The flow-performance relationship is important for investment businesses to understand because of the significant implications this has on the profitability of funds. The research applies a portfolio time-series methodology to Morningstar’s South African fund data, using a buy-and-hold analysis. Two unit trust categories are tested, namely General Equity and Multiasset High Equity funds, and within each category, single manager funds and fund of funds are tested separately. Funds are ranked by their past performance over an optimised 14- month look-back period, and assigned into quintiles. Net flows into each fund in the subsequent quarter are then determined, and the process rolled over on a quarterly basis from 2000 to 2015. We find convincing evidence from an emerging market perspective that equity funds need to perform in the top quintile to attract funds, and observe that relative performance to peers is more important to investors than performance relative to other benchmarks. One additional inference is that the South African unit trust industry is set to face consolidation.http://www.tandfonline.com/loi/riaj202019-01-30am2018Gordon Institute of Business Science (GIBS

Controlled deposition of lead iodide and lead chloride thin films by low-pressure chemical vapor deposition

Lead halide thin films, such as lead iodide (PbI2) and lead chloride (PbCl2), are used as precursor films for perovskite preparation, which is frequently achieved by vacuum thermal evaporation but rarely by the low-pressure chemical vapor deposition (CVD) method. Here, we report on the deposition of PbI2 and PbCl2 thin films on glass substrates by employing the low-pressure CVD method. The effect of the substrate temperature on the structure and morphology of the lead halide films is investigated. Crystalline films were realized for both lead halides, with PbI2 films showing high texture compared to the reduced texture of the PbCl2 films. Large lateral grain sizes were observed for the PbI2 films with a flat platelet grain morphology and an average grain size up to 734.2 ± 144.8 nm. PbCl2 films have columnar grains with an average grain size up to 386.7 ± 119.5 nm. The PbI2 films showed a band gap of about 2.4 eV, confirming its semiconducting properties, and the PbCl2 had a wide band gap of 4.3 eV, which shows the insulating properties of this material

An investigation of the efficiency of South Africa’s sector education and training authorities (SETA’s)

The performance of South African Sector Education and Training Authorities (SETA’s) has been increasingly questioned. On this premise, the paper investigated the efficiency of the SETAs with respect to their utilization of funds in order to promote a range of education and training outputs was investigated. More specifically, the study investigated the quantity and quality of five training and education outputs, set by the National Skills Development Strategy (NSDS), in relation to the funding received. Furthermore, the study examined the amount of money spend on administrative expenditure by the various SETAs, as well as the SETAs management of financial reserves. In order to guide the study, as well as analyze the data, a conceptual framework to measure efficiency was based on an input-output model developed by Gupta and Verhoeven (2001). Data were obtained from the published accounting and annual reports for the period 2006 – 2009. The results indicated only two of the SETA’s were efficient with respect to their utilization of funds and that only five SETA’s consistently met their own targets. The study also shows that if the SETA’ s funds had been applied to education and training outputs, rather than for investment purposes, training outputs could have been considerably increased. The paper has implications for the use of public funds with respect to the critical skills shortage confronting the economy

Correction: Delayed Goblet Cell Hyperplasia, Acetylcholine Receptor Expression, and Worm Expulsion in SMC-Specific IL-4Rα–Deficient Mice

Interleukin 4 receptor alpha (IL-4Ralpha) is essential for effective clearance of gastrointestinal nematode infections. Smooth muscle cells are considered to play a role in the type 2 immune response-driven expulsion of gastrointestinal nematodes. Previous studies have shown in vitro that signal transducer and activator of transcription 6 signaling in response to parasitic nematode infection significantly increases smooth muscle cell contractility. Inhibition of the IL-4Ralpha pathway inhibits this response. How this response manifests itself in vivo is unknown. In this study, smooth muscle cell IL-4Ralpha-deficient mice (SM-MHC(Cre)IL-4Ralpha(-/lox)) were generated and characterized to uncover any role for IL-4/IL-13 in this non-immune cell type in response to Nippostrongylus brasiliensis infection. IL-4Ralpha was absent from alpha-actin-positive smooth muscle cells, while other cell types showed normal IL-4Ralpha expression, thus demonstrating efficient cell-type-specific deletion of the IL-4Ralpha gene. N. brasiliensis-infected SM-MHC(Cre)IL-4Ralpha(-/lox) mice showed delayed ability to resolve infection with significantly prolonged fecal egg recovery and delayed worm expulsion. The delayed expulsion was related to a delayed intestinal goblet cell hyperplasia, reduced T helper 2 cytokine production in the mesenteric lymph node, and reduced M3 muscarinic receptor expression during infection. Together, these results demonstrate that in vivo IL-4Ralpha-responsive smooth muscle cells are beneficial for N. brasiliensis expulsion by coordinating T helper 2 cytokine responses, goblet hyperplasia, and acetylcholine responsiveness, which drive smooth muscle cell contractions

Influence of Synthesis Method on Structural, Morphological, Magnetic, and Antimicrobial Properties of Fe-Ag Nanoparticles

This contribution reports on the development of two versatile and efficient methods, namely the green and gamma radiolysis for Fe-Ag nanoparticles (NPs) synthesis, characterization, and further their growth inhibition potential on some spoilage microorganisms. Green Ag/Fe2O3 NPs were obtained at Fe-Ag [3:1], annealing temperature of 800 °C for 2 h, and gamma irradiated Ag/Fe3O4 NPs were obtained at Fe-Ag [7:1], a 50 kGy dose. The characterization techniques were performed with these two samples whereby the sizes from crystallographic and microscopic analyses were 39.59 and 20.00 nm for Ag/Fe2O3 NPs, 28.57 and 15.37 nm for Ag/Fe3O4 NPs, respectively. The polycrystallinity nature observed from X-ray diffraction was in accordance with the selected area electron diffraction. The vibrational properties confirmed the presence of bimetallic Fe-Ag NPs with the depiction of chemical bonds, Fe–O and Ag–O from attenuated total reflection-Fourier transform infrared spectroscopy and elements Ag, Fe, O from energy-dispersive X-ray spectroscopy analyses. The magnetic properties carried out using a vibrating sample magnetometer suggested a superparamagnetic behavior for the Ag/Fe2O3 NPs and a ferromagnetic behavior for the Ag/Fe3O4 NPs. Overall, the green Ag/Fe2O3 NPs successfully inhibited the growth of spoilage yeasts Candida guilliermondii, Zygosaccharomyces fermentati, Zygosaccharomyces florentinus, and spoilage molds Botrytis cinerea, Penicillium expansum, Alternaria alstroemeriae

Deletion of IL-4Rα on CD4 T Cells Renders BALB/c Mice Resistant to Leishmania major Infection

Effector responses induced by polarized CD4(+) T helper 2 (Th2) cells drive nonhealing responses in BALB/c mice infected with Leishmania major. Th2 cytokines IL-4 and IL-13 are known susceptibility factors for L. major infection in BALB/c mice and induce their biological functions through a common receptor, the IL-4 receptor α chain (IL-4Rα). IL-4Rα–deficient BALB/c mice, however, remain susceptible to L. major infection, indicating that IL-4/IL-13 may induce protective responses. Therefore, the roles of polarized Th2 CD4(+) T cells and IL-4/IL-13 responsiveness of non-CD4(+) T cells in inducing nonhealer or healer responses have yet to be elucidated. CD4(+) T cell–specific IL-4Rα (Lck(cre)IL-4Rα(−/lox)) deficient BALB/c mice were generated and characterized to elucidate the importance of IL-4Rα signaling during cutaneous leishmaniasis in the absence of IL-4–responsive CD4(+) T cells. Efficient deletion was confirmed by loss of IL-4Rα expression on CD4(+) T cells and impaired IL-4–induced CD4(+) T cell proliferation and Th2 differentiation. CD8(+), γδ(+), and NK–T cells expressed residual IL-4Rα, and representative non–T cell populations maintained IL-4/IL-13 responsiveness. In contrast to IL-4Rα(−/lox) BALB/c mice, which developed ulcerating lesions following infection with L. major, Lck(cre)IL-4Rα(−/lox) mice were resistant and showed protection to rechallenge, similar to healer C57BL/6 mice. Resistance to L. major in Lck(cre)IL-4Rα(−/lox) mice correlated with reduced numbers of IL-10–secreting cells and early IL-12p35 mRNA induction, leading to increased delayed type hypersensitivity responses, interferon-γ production, and elevated ratios of inducible nitric oxide synthase mRNA/parasite, similar to C57BL/6 mice. These data demonstrate that abrogation of IL-4 signaling in CD4(+) T cells is required to transform nonhealer BALB/c mice to a healer phenotype. Furthermore, a beneficial role for IL-4Rα signaling in L. major infection is revealed in which IL-4/IL-13–responsive non-CD4(+) T cells induce protective responses