Towards alternative media as critical media in Africa

Social media have enhanced and reshaped alternative media in Africa. It was unsurprising, for example, that the February 2016 edition of New African magazine dedicated its cover to protesters from South Africa, under the heading ‘The #ashtag generation: Inside the new protest movements’. It referred to hashtags such as #RhodesMustFall, #FeesMustFall and #ZumaMustFall as having played a critical role in shaping the struggles from below (Nyamnjoh, 2016). [...

Young African diaspora: Global African narratives, media consumption and identity formation

This study focused on identity formation and media consumption among first-generation young Africans in the diaspora. It investigated what it means to be African and the impact of multiple identities and forms of belonging within diasporic communities. Emphasis was on how they experience the diaspora as liminal spaces and subsequently negotiate relationships with other Africans in indeterminate diasporic spaces to construct, redefine, negotiate and even contest identities. Using snowballing and purposive sampling, the study analysed first-hand accounts and interviews informed by personal histories and lived experiences of (1) what they know about Africa; (2) their sense of belonging to Africa; (3) how Africa is represented in the media and (4) their views/attitudes on markers of African identity. Findings indicate that young Africans in the diaspora have a strong sense of belonging to Africa and are actively engaged with different forms of African media such as music and films

Viscoelastic monitoring of starch-based biomaterials in simulated physiological conditions

Dynamic mechanical analysis (DMA) was used to investigate the solid-state rheological behaviour in a starch-based thermoplastic aimed to be used in different biomedical applications. The tested samples were processed by different injection moulding procedures. The dry samples were immersed in a simulated physiological solution and the relevant viscoelastic parameters were monitored against time. The decrease of stiffness due to swelling can be followed in real time, being less pronounced for the composite sample with hydroxyapatite (HA). The temperature control of the liquid bath was found to be very good. Frequency scans were also performed in wet conditions in samples previously immersed during different times, indicating that DMA is a suitable method to control in-vitro the changes on the viscoelastic properties of biomaterials during degradation

Enron And Continental Vending: A Comparison

We have all heard it said that if we don’t learn from history, we are condemned to repeat it.  It appears that we, as the accounting profession, failed to learn from the Continental Vending case that occurred about four decades ago and thus repeated our mistakes in the Enron case.  First, we will give a brief review of the basics of the Continental Vending case since few of us seem to remember it

Final report: Second generation waste package design study

The objectives of this project activity are: to review the current YMP baseline environment and establish corrosion test environments representative of the range of dry to intermittently wet conditions expected in the drifts as a function of time. to demonstrate the oxidation and corrosion resistance of A588 weathering steel and reference Alloy 22 samples in the representative dry to intermittently dry conditions. to evaluate backfill and design features to improve the thermal performance analyses of the proposed second-generation waste packages using existing models developed at UNR

Analysing protein competition on self-assembled mono-layers studied with quartz crystal microbalance

The mechanisms by which proteins adsorb to surfaces of biomaterials have long been of interest. The present work started with the premise that small/hard and large/soft proteins will yield different sets of normalized frequency shift and dissipation signals when studied with a quartz crystal microbalance. The aim was to evaluate the usefulness of these raw data to study protein competition using protein incubations in sequence and from mixtures of albumin (BSA) and gamma-globulin (BGG) at various ratios. Increasing the concentration of BSA decreases the adsorption of subsequently incubated BGG. For BSA/ BGG mixtures the dissipation is similar for all logarithmic molar ratios BGG/BSA below 1 but soon decreases when the molar ratio of BSA/BGG (and opposite for the normalized frequency shift) is above 1, indicating preferential binding of BGG. Modelling indicated that differences in the film shear modulus and viscosity depend more on the properties of the self-assembling mono-layers (SAMs) than on the proteins. Films high in BSA tentatively differ in film shear modulus and viscosity from that of films high in BGG but only on the hydrophobic surfaces. The results were encouraging as the raw data were deemed to be able to point at protein adsorption competition.The authors thank the Portuguese National Science and Technology Foundation (FCT) for the Project Grants PTDC/FIS/68517/2006 and PTDC/FIS/68209/2006, and personal Grant BPD/39331/2007 for J.B

Synthesis and characterization of N-methylenephenyl phosphonic chitosan

Chitosan is a natural based polymer obtained by alkaline deacetylation of chitin, exhibiting excellent properties such as non‐toxicity, biocompatibility and biodegradability. N‐Methylenephenyl phosphonic chitosan (NMPPC) is synthesized from chitosan by reacting with phenyl phosphonic acid using formaldehyde. The NMPPC was characterized by FTIR, 31P‐NMR, X‐ray diffraction, scanning electron microscopy, thermogravimeteric analysis and solubility studies. A significant decrease of molecular weight was observed in the NMPPC. The TGA studies suggested that NMPPC has less thermal stability than chitosan. The X‐ray diffraction analysis showed that NMPPC was amorphous in nature. The solubility property of the polymer was improved after the incorporation of a phenyl phosphonic grou

Chemistry and applications of phosphorylated chitin and chitosan

Chitin and chitosan are natural based non-toxic, biodegradable and biocompatible polymers and have been used in biomedical areas in the form of sutures, wound healing materials and artificial skin, and for the sustained release of drugs as well as in various industrial applications. However, practical use of these polymers has been mainly confined to the unmodified forms. Recently, there has been a growing interest in chemical modification of chitin and chitosan to improve their solubility and widen their applications. Among them, phosphorylated chitin and chitosan have attracted considerable interest because of their various advantages: anti-inflammatory property, ability to form metal complexes, blood compatibility and formation of anionic polyelectrolyte hydrogels. The purpose of this review is to take a closer look of different synthetic methods of phosphorylated chitin and chitosan and their potential applications in environmental, food, fuel cell, and biomedical fields. Based on current research and existing products, some new and futuristic approaches in this context area are discussed.R. Jayakumar acknowledges the Portuguese Foundation for Science and Technology for providing him a Post-Doc scholarship (SFRH/BPD/14670/2003). This work was partially supported by FCT Foundation for Science and Technology, through funds from the POCTI and/or FEDER program. This work was partially supported by the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758)

Preparation and in vitro characterization of scaffolds of poly(L-lactic acid) containing bioactive glass ceramic nanoparticles

Porous nanocomposite scaffolds of poly(L-lactic acid) (PLLA) containing different quantities of bioactive glass ceramic (BGC) nanoparticles (SiO2:CaO:P2O5 ! 55:40:5 (mol)) were prepared by a thermally induced phase-separation method. Dioxane was used as the solvent for PLLA. Introduction of less than 20 wt.% of BGC nanoparticles did not remarkably affect the porosity of PLLA foam. However, as the BGC content increased to 30 wt.%, the porosity of the composite was observed to decrease rapidly. The compressive modulus of the scaffolds increased from 5.5 to 8.0 MPa, while the compressive strength increased from 0.28 to 0.35 MPa as the BGC content increased from 0 to 30 wt.%. The in vitro bioactivity and biodegradability of nanocomposites were investigated by incubation in simulated body fluid (SBF) and phosphate-buffered saline, respectively. Scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction were employed to monitor the surface variation of neat PLLA and PLLA/ BGC porous scaffolds during incubation. PLLA/(20 wt.%)BGC composite exhibited the best mineralization property in SBF, while the PLLA/(10 wt.%)BGC composite showed the highest water absorption ability.This work was financially supported by FCT Grant for postdoctoral research (SFRH/BPD/25828/2005), and by the Projects POCTI/FIS/61621/2004 and PTDC/QUI/69263/2006. The authors also would like to acknowledge Dr. Aixue Liu, Changchun Institute of Applied Chemistry, for his help in characterization of composite material