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Applications of advanced materials in bio-sensing in live cells : methods and applications
Get PDFAbstract: A wide variety of species, such as different ions, reactive oxygen species, and biomolecules play critical roles in many cell functions. These species are responsible for a range of cellular functions such as signaling, and disturbed levels could be involved in many diseases, such as diabetes, cancer, neurodegeneration etc. Thus, sensitive and specific detection methods for these biomarkers could be helpful for early disease detection and mechanistic investigations. New ultrasensitive sensors for detection of markers within living cells are a growing field of research. The present review provides updates in live cell-based biosensing, which have been published within the last decade. These sensors are mainly based on carbon, gold and other metals, and their physicochemical advantages and limitations are discussed. Advanced materials can be incorporated into probes for the detection of various analytes in living cells. The sensitivity is strongly influenced by the intrinsic properties of the nanomaterials as well their shape and size. The mechanisms of action and future challenges in the developments of new methods for live cell based biosensing are discussed
Transcranial photobiomodulation prevents PTSDlike comorbidities in rats experiencing underwater trauma
Get PDFAbstract: Maladaptive fear memory processing after a traumatic event is a major contributor to the development of the comorbidities related to posttraumatic stress disorder (PTSD). An intervention to normalize this process could be a first-line treatment to prevent PTSD development. However, little progress has been made in identifying interventions that can prevent trauma survivors from developing PTSD. A treatment that could help trauma survivors cope with traumatic memories and decrease the prevalence of PTSD is thus in high demand. This study was designed to investigate the potential beneficial effects of early photobiomodulation (PBM) interventions to prevent PTSD-like comorbidities in animals. PTSD-like comorbidities in rats were induced by an underwater trauma (UWT) procedure, followed by multiple swimming sessions on later days for memory recall. Immediately after UWT and swimming, rats were restrained with or without PBM treatment (808 nm, 25 mW/cm2, 3 J/day). PTSD-like commodities, such as anxietylike behavior, depression-like behavior, and cognitive dysfunction, were reproduced in UWT-rats. These comorbidities, however, could be prevented by early PBM interventions. By measuring the expression of immediate early genes (IEGs) as neuronal activity markers, we found that PBM treatment differentially regulated Arc and c-fos expression in the hippocampus and amygdala, two PTSD-related brain regions. Additionally, PBM boosted ATP production and regulated protein expression in the hippocampus following stress. Our results demonstrate that PBM can modulate brain activity in response to traumatic and stressful events and that early PBM intervention can prevent the occurrence of PTSD-like comorbidities in rats
Obstacles to Venture Capital Funding : the South African entrepreneurs’ perspective
Get PDFAbstract: The primary objective of this qualitative study was to explore the challenges faced by entrepreneurs in acquiring funding from venture capitalist companies in South Africa. A purposive snowball sampling technique was adopted to collect data from ten entrepreneurs and ten venture capitalist companies using semi-structured face-to-face interviews. Thematic analysis of the data revealed a number of prominent themes. Findings indicated that venture capitalist investors consider personal qualities of the entrepreneur as a key indicator of a viable business opportunity when making investment decisions. It was further revealed that the investment evaluation process is both lengthy and costly. In South Africa, the economic and political environments are unstable and risky. This plays an influential role to venture capitalist investors when making investment decisions. The study contributes to the existing body of knowledge and points to issues that can be further investigated. The study also has managerial implications in that it provides guidelines to entrepreneurs on how to approach venture capitalist investors for investment. The study has some limitations in that the use of a non-probability sampling techniques implies that findings cannot be generalised widely. Furthermore, the study was conducted only in South Africa and findings therefore cannot be generalised across other markets
Exploring the challenges in leadership roles experienced by nurse managers in a mining primary healthcare setting in South Africa
Get PDFAbstract: Background: The challenges in leadership roles hinder the rendering of quality primary healthcare service in the mines. Mining, the heart of the South African economy, requires good health to its personnel to carry out operations. However, nurse managers, the leaders in a mining primary healthcare setting experience difficulties in their leadership roles. Objectives: The aim of this study was to explore and describe the challenges in leadership roles experienced by nurse managers in a mining primary healthcare setting in South Africa. Method: The study was conducted in a mining primary healthcare setting in West Rand, Gauteng province, South Africa. A qualitative, exploratory, descriptive design that is contextual in nature, using a phenomenological approach, was adopted. Data from nurse managers in the mine were collected and data saturation was reached by the seventh participant. The study followed Giorgi’s four stages of the phenomenological descriptive data analysis. An expert independent coder in qualitative research coded the data, and consensus on the findings was reached with the researcher. Results: Three subthemes emerged from the study: mining management and unions interfere with nurse managers’ leadership roles, incongruent mining primary healthcare policies and communication gap between nurse managers and mining management. Conclusion: The triangulation of nurse managers, mining management and unions requires a collective fusion to directly tackle the challenges in leadership roles in mining primary healthcare
Performance characteristics of unsaturated polyester reinforced with high frequency microwave treated natural fibre
Get PDFAbstract: Using the most environmentally sustainable agro-waste fibers as reinforcement has opened up a new direction for polymer composite research. Research has recommended that altering of fibre surface by both chemical and physical means, increases the performance characteristic of natural fibre/polymer matrix. In this study, high-frequency microwave irradiation at a frequency of 2.45 GHZ and 550W power was used to treat natural fibre extracted from plantain (Musa paradisiacal) pseudo steam. Microwave modified and untreated plantain fibre was used to fabricate a biocomposite using polyester resin as polymer matrix, by means of hand lay-up and compression moulding technique. Results reveal an increase in mechanical strength of the modified fibre reinforced bio-composites at optimised conditions, thus creating opportunities and consistency to be use in technological and structural applications
Measurements of and production in the -bb decay channel in collisions at 13TeV with the ATLAS detector
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Measurement of hadronic event shapes in high- T multijet final states at √ = 13 TeV with the ATLAS detector
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Stakeholder and visitor reflections of sport brand positioning in South Africa
Get PDFAbstract: The purpose of this paper was to identify stakeholder and visitor perceptions of brand images of the South African destination brand in order to examine how sport is utilised as a catalytic agent for achieving brand positioning. Following a mixed method approach, in-depth semi-structured interviews were conducted with 24 sport, tourism, and government stakeholders. Survey questionnaires were administered with 403 sport event visitors at major events across South Africa. The results show congruence between stakeholder and sport event visitor perceptions on the multi-layered brand images of South Africa. Uniquely defined city brand images raise challenges and opportunities for establishing a coherent national brand positioning. The utilisation of sport for brand positioning is greatly dependent on brand distinctiveness and dedicated stakeholder vision and policy. The study provides a framework of recommendations that practically guide key industry stakeholders on value propositions that underpin brand positioning strategies. This study also makes a contribution to existing brand positioning theories and practice by exploring the value proposition construct to a unique sport environment while employing real-life destination brand scenarios
Participation and communication behaviour at academic conferences – An empirical gender study at the German Congress of Geography 2019
Get PDFAbstract: This article examines gender differences in participation and communication behaviour at the German Congress of Geography 2019 in Kiel. The programme booklet and over 70 sessions with more than 200 lectures as well as over 800 discussion contributions were analysed for gender-specific differences using a standardised structured observation form. The results show significant gender differences both on the level of participation and on the level of communication behaviour: Lectures delivered by men achieved higher attendance figures than lectures by women due to gender-selective attendance behaviour of men; women were under-represented in the role of session chair; men tended to dominate the discussion rounds after the presentations, they took the floor more often and talked longer; the session chairs’ gender exercised a decisive influence on who participated in the discussions, there was a clear tendency towards gender homophily; in general, discussion activity was higher after presentations by women, because women then participated in the discussions significantly more often and for longer periods of time. In the second part of the paper, we put our findings in historical context. This reveals that gender inequality has decreased e.g. with regard to women’s conference participation, personnel structure and the number of women being appointed as full professors. On a structural level, positive gender dynamics are emerging within German-speaking geography. On the other hand, it becomes evident that especially at the level of communication at conferences, traditional gender-specific behaviours do persist. These behavioural patterns are obviously more enduring than the formal structures and positions
Macadamia nutshell decorated polyaniline nanocomposites (MNS-PANI) for the removal of CR(VI) and its re-use for photocatalytic degradation
Get PDFAbstract: This study investigated a polyaniline decorated macadamia nutshell composite (MNS-PANI) adsorbent for the removal of highly toxic Cr(VI) and the efficient catalytic activity of the spent adsorbent for reuse. The composite adsorbent was successfully synthesised and the functional groups present were confirmed with Fourier transform infrared spectroscopy (FTIR). The diffraction patterns were examined with X-ray diffractometry (XRD) while the structure and surface morphology were assessed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elemental composition of the adsorbent was studied using energy dispersive X-ray spectrometer (EDX) Brunauer-Emmett-Teller (BET) was used to estimate the surface area while the thermal stability was studied using thermogravimetric analyser. Batch adsorption studies were further carried out to study the adsorptive behaviour of MNS-PANI with Cr(VI), and the effects of pH, contact time, adsorbent dose, initial Cr(VI) concentration and temperature were studied. The Cr(VI) loaded MNS-PANI was further applied in the degradation of ciprofloxacin...M.Sc. (Chemistry
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