Real-time imaging of novel spatial and temporal responses to photodynamic stress.

Cells subjected to various forms of stress have been shown to induce bystander responses in nontargeted cells, thus extending the stress response to a larger population. However, the mechanism(s) of bystander responses remains to be clearly identified, particularly for photodynamic stress. Oxidative stress and cell viability were studied on the spatial and temporal levels after photodynamic targeting of a subpopulation of EMT6 murine mammary cancer cells in a multiwell plate by computerized time-lapse fluorescence microscopy. In the targeted population a dose-dependent loss of cell viability was observed in accordance with increased oxidative stress. This was accompanied by increased oxidative stress in bystander populations but on different time scales, reaching a maximum more rapidly in targeted cells. Treatment with extracellular catalase, or the NADPH oxidase inhibitor diphenyleneiodinium, decreased production of reactive oxygen species (ROS) in both populations. These effects are ascribed to photodynamic activation of NADPH-oxidase in the targeted cells, resulting in a rapid burst of ROS formation with hydrogen peroxide acting as the signaling molecule responsible for initiation of these photodynamic bystander responses. The consequences of increased oxidative stress in bystander cells should be considered in the overall framework of photodynamic stress.

The feminine character and temporal freedom in three historical novels by Angelina Muñiz: Morada interior (1972), "El Mercader de Tudela" (1995) y "La Burladora de Toledo" (2008)

We focus on the representation of time in Muñiz’s historical novels. Concretely, we stress the attitude of the feminine characters towards time and history. Muñiz’s female personages continuously transgress temporal borders and move freely between different historical periods. We relate Muñiz’s particular vision on time and on the separation lines between historical periods to her situation as an exile. The author is continuously crossing borders between the past of her homeland and the present of her adoptive country. We argument Muñiz is recreating this “borderfree” attitude towards time in the female characters of her historical novels.

Between “the Housewife” and “the Philosophy Professor”: Music, Narration and Address in Ousmane Sembene's Xala

The acclaimed Senegalese filmmaker Ousmane Sembene conceptualised himself as a modern day griot (West African oral performer), producing often didactic films that address a diverse spectatorship. Examining Xala, this paper argues that this address cannot be fully understood without attention to the film’s complex music/image relationships, which refigure classical and modernist film aesthetics to mobilise a discourse that recalls oral performance. In this way, Sembene negotiates the tensions of address generated by a spectatorship that is situated in the culturally hybrid spaces between the literate and the oral, the urban and the rural, and the global and the local.

Using time-to-contact information to assess potential collision modulates both visual and temporal prediction networks

Accurate estimates of the time-to-contact (TTC) of approaching objects are crucial for survival. We used an ecologically valid driving simulation to compare and contrast the neural substrates of egocentric (head-on approach) and allocentric (lateral approach) TTC tasks in a fully factorial, event-related fMRI design. Compared to colour control tasks, both egocentric and allocentric TTC tasks activated left ventral premotor cortex/frontal operculum and inferior parietal cortex, the same areas that have previously been implicated in temporal attentional orienting. Despite differences in visual and cognitive demands, both TTC and temporal orienting paradigms encourage the use of temporally predictive information to guide behaviour, suggesting these areas may form a core network for temporal prediction. We also demonstrated that the temporal derivative of the perceptual index tau (tau-dot) held predictive value for making collision judgements and varied inversely with activity in primary visual cortex (V1). Specifically, V1 activity increased with the increasing likelihood of reporting a collision, suggesting top-down attentional modulation of early visual processing areas as a function of subjective collision. Finally, egocentric viewpoints provoked a response bias for reporting collisions, rather than no-collisions, reflecting increased caution for head-on approaches. Associated increases in SMA activity suggest motor preparation mechanisms were engaged, despite the perceptual nature of the task.

"Thought-Tormented Music": Joyce and the Music of the Irish Revival

"In this special issue's opening essay, Martin Dowling devotes almost half of "'Thought-Tormented Music': Joyce and the Music of the Irish Revival" to what he calls "the situation of music in the Irish literary revival." He focuses chiefly on 1904, which was both an intensely productive period for the revival movement and a year chock-full of crucial events and decisions for Joyce. Drawing on the works of Pierre Bourdieu and Jaques Lacan, Dowling explores the revivalists' efforts to "de-anglicize" Irish music, to remove foreign influences that distorted the "pure tradition of Irish song," and to achieve an improbable harmony between the music favoured by the disappearing Anglo-Irish aristocracy and the Irish-speaking peasantry. Inevitably, disputes occurred over what constituted "authentic" Irish music. Factions quarrelled over whether pristine Irish music existed in the Atlantic seaboard or more inland; whether "authentic" songs were sung with or without instrumental accompaniment; and whether the piano, rather than the traditional harp, was a legitimate instrument of accompaniment. Having delineated the historical and theoretical context, Dowling offers a richly detailed analysis of Joyce's story "A Mother." He reveals how almost every element in the story--from the Eire Abu Society to the Antient Concert Rooms, from the conflict between Mrs. Kearney and Hoppy Holohan to the plight of Kathleen Kearney--is charged with meaning by the subtextual conflicts of the revivalists' agenda. Dowling explains also the "authenticity" in Joyce's depiction of vocal performances of "The Lass of Aughrim" in "The Dead" and "The Croppy Boy" in "Sirens," which he calls two "true gems" of authentic Irish music." --Introduction by Charles Rossman and Alan W. Friedman, Guest Editors, pp. 409-410

Molecular cloning and deduced organization of the pHpG/CNP precursor from the venom of the African forest viper, Atheris squamigera

The discovery that the hypotensive sequela of envenomation by the South American viper, Bothrops jararaca, was mediated by peptides, represented a milestone in drug discovery research that led to the introduction of ACE inhibitors. These bradykinin-potentiating peptides (BPPs) have been found in the venoms of many species of viper and molecular cloning of biosynthetic precursors has revealed that each encodes several different BPPs in tandem with a single copy of a C-type natriuretic peptide (CNP) located at the C-terminus. Venoms of the African forest vipers (Atheris) have been poorly studied possibly because they do not represent a major danger to humans. However, initial studies have indicated that they contain some of the “classical” protein toxins of viper venoms and a novel class of peptide, the polyglycine/polyhistidine (pGpH) peptides. These peptides occur in several molecular forms with different numbers of repetitive glycine and histidine repeats. We have cloned the biosynthetic precursor of A. squamigera pGpH peptides from a venom-derived cDNA library and have confirmed that a single copy of CNP is located at the C-terminus and additionally that, like BPPs in other vipers, pGpH peptides are encoded in tandem within this single precursor. Solid phase peptide synthesis of pGpH peptides has proven to be extremely difficult but is progressing and acquisition of synthetic replicates of each peptide is a necessary prerequisite for systematic pharmacological characterisation as establishment of a biological function for these peptides remains elusive. pGpH peptides may prove to play a role as fundamental as that of the BPPs.

SpaciMS: spatial and temporal operando resolution of reactions within catalytic monoliths

Monolithic catalysts are widely used as structured catalysts, especially in the abatement of pollutants. Probing what happens inside these monoliths during operation is, therefore, vital for modelling and prediction of the catalyst behavior. SpaciMS is a spatially resolved capillary-inlet mass spectroscopy system allowing for the generation of spatially resolved maps of the reactions within monoliths. In this study SpaciMS results combined with 3D CFD modelling demonstrate that SpaciMS is a highly sensitive and minimally invasive technique that can provide reaction maps as well as catalytic temporal behavior. Herein we illustrate this by examining kinetic oscillations during a CO oxidation reaction over a Pt/Rh on alumina catalyst supported on a cordierite monolith. These oscillations were only observed within the monolith by SpaciMS between 30 and 90% CO conversion. Equivalent experiments performed in a plug-flow reactor using this catalyst in a crushed form over a similar range of reaction conditions did not display any oscillations demonstrating the importance of intra monolith analysis. This work demonstrates that the SpaciMS offers an accurate and comprehensive picture of structured catalysts under operation.