The new Africans: a textual analysis of the construction of 'African-ness' in Chaz Maviyane-Davies' 1996 poster depictions of the Universal Declaration of Human Rights

In 1996, Zimbabwean graphic designer Chaz Maviyane-Davies created a set of human rights posters which represent several articles of the Universal Declaration of Human Rights, from what he calls an “African perspective”. In this study I investigate how Maviyane-Davies has constructed ‘African-ness’ and probe what he refers to as the “alternative aesthetic” that he is trying to create. I use a visual social semiotic approach to examine the discourses he draws on to re-image and re-imagine Africa and Africans in a manner that contests the stereotypical representations found in political, news and economic discourses about Africa, paying particular attention to the ways he uses images of the body. My analysis of the posters shows how complex and difficult it can be to contest regimes of representation that work to fix racialised and derogatory meanings. In response to the pejorative stereotypes of the black body, Maviyane-Davies uses images of strong, healthy, and magnificent people (mostly men) to construct a more affirmative representation of Africa and Africans. Significantly, he draws on sports, touristic, traditional and hegemonic discourses of masculinity in an attempt to expand the complexity and range of possible representations of African-ness. In so doing he runs the risk of reproducing many of the stereotypes that sustain not only the racialised and gendered (masculinist) representations of Africa, but also a sentimentalisation and romanticisation of a place, a people and their traditions. Apart from women in prominent positions, other conspicuous absences from these images include white people and hegemonic references to Western modernity. I do not believe he is discarding whites and modernity as un-African, but is rejecting the naturalisation of whiteness as standing in for humanity, and particular icons of Western modernity as significations of ‘modernity’ itsel

Burnout in the ICU : potential consequences for staff and patient well-being

Peer reviewedAuthor versio

CaMKII binds both substrates and activators at the active site [preprint]

Ca2+/calmodulin dependent protein kinase II (CaMKII) is a signaling protein that is required for long-term memory formation. Ca2+/CaM activates CaMKII by binding to its regulatory segment, thereby freeing the substrate binding site. Despite having a large variety of interaction partners, the specificity of CaMKII interactions have not been structurally well-characterized. One exceptional feature of this kinase is that interaction with specific binding partners persistently activates CaMKII. To address the molecular details of this, we solved X-ray crystal structures of the CaMKII kinase domain bound to four different binding partners that modulate CaMKII activity in different ways. We show that all four partners bind in the same manner across the substrate binding site. We generated a sequence alignment based on our structural observations, which revealed conserved interactions. Using biochemistry and molecular dynamics simulations, we propose a mechanistic model that persistent CaMKII activity is facilitated by high affinity binding partners, which compete with the regulatory segment to allow substrate phosphorylation

Development and evolution of dentition pattern and tooth order in the Skates and Rays (Batoidea; Chondrichthyes)

Shark and ray (elasmobranch) dentitions are well known for their multiple generations of teeth, with isolated teeth being common in the fossil record. However, how the diverse dentitions characteristic of elasmobranchs form is still poorly understood. Data on the development and maintenance of the dental patterning in this major vertebrate group will allow comparisons to other morphologically diverse taxa, including the bony fishes, in order to identify shared pattern characters for the vertebrate dentition as a whole. Data is especially lacking from the Batoidea (skates and rays), hence our objective is to compile data on embryonic and adult batoid tooth development contributing to ordering of the dentition, from cleared and stained specimens and micro-CT scans, with 3D rendered models. We selected species (adult and embryonic) spanning phylogenetically significant batoid clades, such that our observations may raise questions about relationships within the batoids, particularly with respect to current molecular-based analyses. We include developmental data from embryos of recent model organisms Leucoraja erinacea and Raja clavata to evaluate the earliest establishment of the dentition. Characters of the batoid dentition investigated include alternate addition of teeth as offset successional tooth rows (versus single separate files), presence of a symphyseal initiator region (symphyseal tooth present, or absent, but with two parasymphyseal teeth) and a restriction to tooth addition along each jaw reducing the number of tooth families, relative to addition of successor teeth within each family. Our ultimate aim is to understand the shared characters of the batoids, and whether or not these dental characters are shared more broadly within elasmobranchs, by comparing these to dentitions in shark outgroups. These developmental morphological analyses will provide a solid basis to better understand dental evolution in these important vertebrate groups as well as the general plesiomorphic vertebrate dental condition

Stylized facts of intraday precious metals

This paper examines the stylized facts, correlation and interaction between volatility and returns at the 5-minute frequency for gold, silver, platinum and palladium from May 2000 to April 2015. We study the full sample period, as well as three subsamples to determine how high-frequency data of precious metals have developed over time. We find that over the full sample, the number of trades has increased substantially over time for each precious metal, while the bid-ask spread has narrowed over time, indicating an increase in liquidity and price efficiency. We also find strong evidence of periodicity in returns, volatility, volume and bid- ask spread. Returns and volume both experience strong intraday periodicity linked to the opening and closing of major markets around the world while the bid-ask spread is at its low- est when European markets are open. We also show a bilateral Granger causality between returns and volatility of each precious metal, which holds for the vast majority subsamples

Managerial Responses to Incentives: Control of Firm Risk, Derivative Pricing Implications, and Outside Wealth Management

We model a firm’s value process controlled by a manager maximizing expected utility from restricted shares and employee stock options. The manager also dynamically controls allocation of his outside wealth. We explore interactions between those controls as he partially hedges his exposure to firm risk. Conditioning on his optimal behavior, control of firm risk increases the expected time to exercise for his employee stock options. It also reduces the percentage gap between his certainty equivalent and the firm’s fair value for his compensation, but that gap remains substantial. Managerial control also causes traded options to exhibit an implied volatility smile

Integrated genomic characterization of oesophageal carcinoma

Oesophageal cancers are prominent worldwide; however, there are few targeted therapies and survival rates for these cancers remain dismal. Here we performed a comprehensive molecular analysis of 164 carcinomas of the oesophagus derived from Western and Eastern populations. Beyond known histopathological and epidemiologic distinctions, molecular features differentiated oesophageal squamous cell carcinomas from oesophageal adenocarcinomas. Oesophageal squamous cell carcinomas resembled squamous carcinomas of other organs more than they did oesophageal adenocarcinomas. Our analyses identified three molecular subclasses of oesophageal squamous cell carcinomas, but none showed evidence for an aetiological role of human papillomavirus. Squamous cell carcinomas showed frequent genomic amplifications of CCND1 and SOX2 and/or TP63, whereas ERBB2, VEGFA and GATA4 and GATA6 were more commonly amplified in adenocarcinomas. Oesophageal adenocarcinomas strongly resembled the chromosomally unstable variant of gastric adenocarcinoma, suggesting that these cancers could be considered a single disease entity. However, some molecular features, including DNA hypermethylation, occurred disproportionally in oesophageal adenocarcinomas. These data provide a framework to facilitate more rational categorization of these tumours and a foundation for new therapies

Spatio-Temporal Models of Juvenile and Adult Sheepshead (Archosargus probatocephalus) in Tampa Bay, Florida from 1996 to 2016

Spatio-temporal distribution models for juvenile and adult Sheepshead (Archosargus protocephalus) were developed for Tampa Bay, FL using Boosted Regression Trees. Juvenile Sheepshead were primarily associated with month of collection (highest occurrence in May and June), low salinities (\u3c10), and increased distance from a tidal inlet. Adult Sheepshead were more frequently detected closer to inlets in September through November, with an increasing trend through time, and had the highest probability of detection in areas with the highest salinity levels. Our results indicate that juvenile Sheepshead are associated with tidal tributaries on the east side of Tampa Bay and adult Sheepshead are associated with the major inlet into the Gulf of Mexico. These findings reflect seasonal and ontogenetic shifts in distribution that are necessary to inform spatially-based management approaches and to prioritize areas for habitat conservation

Attenuation of IgE Affinity for FcεRI Radically Reduces the Allergic Response in Vitro and in Vivo*

The high affinity of IgE for its receptor, FcεRI (Ka ∼ 1010 m–1), is responsible for the persistence of mast cell sensitization. Cross-linking of FcεRI-bound IgE by multivalent allergen leads to cellular activation and release of pro-inflammatory mediators responsible for the symptoms of allergic disease. We previously demonstrated that limiting the IgE-FcεRI interaction to just one of the two Cε3 domains in IgE-Fc, which together constitute the high affinity binding site, results in 1000-fold reduced affinity. Such attenuation, effected by a small molecule binding to part of the IgE:FcεRI interface or a distant allosteric site, rather than complete blocking of the interaction, may represent a viable approach to the treatment of allergic disease. However, the degree to which the interaction would need to be disrupted is unclear, because the importance of high affinity for immediate hypersensitivity has never been investigated. We have incorporated into human IgE a mutation, R334S, previously characterized in IgE-Fc, which reduces its affinity for FcεRI ∼50-fold. We have compared the ability of wild type and R334S IgE to stimulate allergen-induced mast cell activation in vitro and in vivo. We confirmed the expected difference in affinity between wild type and mutant IgE for FcεRI (∼50-fold) and found that, in vitro, mast cell degranulation was reduced proportionately. The effect in vivo was also marked, with a 75% reduction in the passive cutaneous anaphylaxis response. We have therefore demonstrated that the high affinity of IgE for FcεRI is critical to the allergic response, and that even moderate attenuation of this affinity has a substantial effect in vivo