When Old Issues Call Forth a New People: A Constitutive Rhetorical Analysis of Black Liberation Manifestos

While much rhetorical research has been dedicated to social movements, not as much scholarship has examined the manifesto texts that form the rhetorical basis for said movements. This essay analyzes whether related rhetorical forms exist across multiple manifesto discourses, specifically elements of constitutive rhetoric, through the study of the UNIA and Black Panther Party’s manifestos. Although the scope of this particular inquiry is too narrow to provide a definitive conclusion, it appears constitutive elements recur enough across black liberation discourses to warrant further discussion on whether manifestos ought to be considered as a separate rhetorical genre

The Energetics and Mass-loss of Mrk33

We present ROSAT HRI X-ray data and optical imaging of the important dwarf starburst Markarian 33. We find an extended, complex, shell-like morphology in the X-ray emission, with an extent of 2.3 x 1.9kpc, coincident with the bright star-forming regions at the centre of the galaxy. The physical extent of this X-ray emission from Mrk 33 is very similar to the observed Halpha emission, and suggests that the bulk of the X-ray emission is coming from an expanding superbubble. We estimate the age and mass of Mrk 33's starburst to be 5.8 Myr and 6.9 x 10^{6} Msolar respectively with the energy injection rate in the central regions of the galaxy being 10^{41} erg/s, while the associated mass-loss rate from the star-forming regions is estimated to be 0.2 Msolar/yr. We suggest that the X-ray emission is predominantly powered by starburst type activity and argue that a blowout in the form of a galactic wind is the most likely fate for Mrk 33 resulting in the loss of most of the galaxy's metal-enriched material and a small fraction (<1 per cent) of the ISM.Comment: 13 pages, 6 figures, accepted for publication in MNRA

Chandra and XMM-Newton Observations of NGC 4214: The Hot Interstellar Medium and the Luminosity Function of Dwarf Starbursts

We present results from Chandra and XMM-Newton X-ray observations of NGC 4214, a nearby dwarf starburst galaxy containing several young regions of very active star-formation. Starburst regions are known to be associated with diffuse X-ray emission, and in this case the X-ray emission from the galaxy shows an interesting morphological structure within the galaxy, clearly associated with the central regions of active star-formation. Of the two main regions of star-formation in this galaxy, X-ray emission associated with the older is identified whereas little is detected from the younger, providing an insight into the evolutionary process of the formation of superbubbles around young stellar clusters. The spectra of the diffuse emission from the galaxy can be fitted with a two temperature component thermal model with kT=0.14keV and 0.52keV, and analysis of this emission suggests that NGC 4214 will suffer a blow-out in the future. The point source population of the galaxy has an X-ray luminosity function with a slope of -0.76. This result, together with those for other dwarf starburst galaxies (NGC 4449 and NGC 5253), was added to a sample of luminosity functions for spiral and starburst galaxies. The slope of the luminosity function of dwarf starbursts is seen to be similar to that of their larger counterparts and clearly flatter than those seen in spirals. Further comparisons between the luminosity functions of starbursts and spiral galaxies are also made.Comment: 16 pages, 12 figures. Accepted for publication in MNRA

New Piperidine alkaloids from fire ants are not sequestered by the green and black poison frog ( Dendrobates auratus )

Neotropical poison frogs possess alkaloid-based antipredator defenses which they sequester from a diet of arthropods such as oribatid mites and myrmicine ants. Alkaloid sequestration is still poorly understood and although several studies have examined its uptake, most experiments directly feed alkaloids to the frogs. Here, we examined the alkaloid uptake system in the poison frog species Dendrobates auratus by feeding it an alkaloid-containing prey item, the red imported fire ant Solenopsis invicta (Formicidae, Myrmicinae). Captive bred frogs were either fed live ants or fruit flies dusted with powdered ants for 4 months. Using GC–MS, we confirm that S. invicta contain previously described piperidine alkaloids known as solenopsins; however, none of these piperidine alkaloids was detected in the skin of D. auratus, suggesting the frogs are incapable of sequestering solenopsins from S. invicta. It is possible that D. auratus are unable to sequester fire ant piperidines due to their long hydrocarbon side chains, a feature that makes them structurally different than most known alkaloids in poison frogs

The role of the lateral prefrontal cortex and anterior cingulate in stimulus–response association reversals

Many complex tasks require us to flexibly switch between behavioral rules, associations, and strategies. The prefrontal cerebral cortex is thought to be critical to the performance of such behaviors, although the relative contribution of different components of this structure and associated subcortical regions are not fully understood. We used functional magnetic resonance imaging to measure brain activity during a simple task which required repeated reversals of a rule linking a colored cue and a left/right motor response. Each trial comprised three discrete events separated by variable delay periods. A colored cue instructed which response was to be executed, followed by a go signal which told the subject to execute the response and a feedback instruction which indicated whether to ‘‘hold’’ or ‘‘f lip’’ the rule linking the colored cue and response. The design allowed us to determine which brain regions were recruited by the specific demands of preparing a rule contingent motor response, executing such a response, evaluating the significance of the feedback, and reconfiguring stimulus–response (SR) associations. The results indicate that an increase in neural activity occurs within the anterior cingulate gyrus under conditions in which SR associations are labile. In contrast, lateral frontal regions are activated by unlikely/unexpected perceptual events regardless of their significance for behavior. A network of subcortical structures, including the mediodorsal nucleus of the thalamus and striatum were the only regions showing activity that was exclusively correlated with the neurocognitive demands of reversing SR associations. We conclude that lateral frontal regions act to evaluate the behavioral significance of perceptual events, whereas medial frontal–thalamic circuits are involved in monitoring and reconfiguring SR associations when necessary

Chandra & XMM-Newton Observations of NGC5253. Analysis of the X-ray Emission from a Dwarf Starburst Galaxy

We present Chandra and XMM-Newton X-ray data of NGC5253, a local starbursting dwarf elliptical galaxy, in the early stages of a starburst episode. Contributions to the X-ray emission come from discrete point sources and extended diffuse emission, in the form of what appear to be multiple superbubbles, and smaller bubbles probably associated with individual star clusters. Chandra detects 17 sources within the optical extent of NGC5253 down to a completeness level corresponding to a luminosity of 1.5E37 erg/s.The slope of the point source X-ray luminosity function is -0.54, similar to that of other nearby dwarf starburst galaxies. Several different types of source are detected within the galaxy, including X-ray binaries and the emission associated with star-clusters. Comparison of the diffuse X-ray emission with the observed Halpha emission shows similarities in their extent. The best spectral fit to the diffuse emission is obtained with an absorbed, two temperature model giving temperatures for the two gas components of ~0.24keV and ~0.75keV.The derived parameters of the diffuse X-ray emitting gas are as follows: a total mass of \~1.4E6 f^{1/2} Msun, where f is the volume filling factor of the X-ray emitting gas, and a total thermal energy content for the hot X-ray emitting gas of \~3.4E54 f^{1/2} erg. The pressure in the diffuse gas is P/k ~ 1E6f^{-1/2}K/cm3. We find that these values are broadly commensurate with the mass and energy injection from the starburst population. Analysis of the kinematics of the starburst region suggest that the stellar ejecta contained within it can escape the gravitational potential well of the galaxy, and pollute the surrounding IGM.Comment: 19 pages, In Press in MNRA

Pictures Not Homes

The project Pictures not Homes is the result of the partial excavation of Taplow House, a South East London estate block earmarked for renewal and ‘bettering’. This is a documentary project using contemporary archaeological recording practices; photogrammetry, reflectance transformation imaging [RTI] and 3D laser scanning. Pictures not Homes is material documentation of the urban regeneration process enabled by new-imaging technologies; the wreckage of place salvaged as file types. The title is a reversal of the slogan ‘HOMES NOT PICTURES’ daubed by protesters across ‘social’ artwork on a demolition site hoarding. This work wanders about appearance and dwelling, through pictures and homes, divisions and productions, data-sets and concrete abstractions. It is also a way to frame questions of what pictures do: questions of capacities, anxiety and ambivalence. It evokes an environment of barricades, sandbags, file types and data as ruin

SUMMARY – living on different incomes in London: can public consensus identify a 'riches line'?

There is widespread public and political concern about economic inequality in the UK today but relatively little research exploring people’s opinions about high incomes, wealth and what it means to be rich. This innovative study aimed to explore what members of the public with lower and higher incomes living in London think defines higher living standards and whether there is a point at which financial resources (income and wealth) are excessive or undesirable for society. London was chosen as the location for the study because economic inequality is particularly pronounced and plainly visible in the capital

Control of the stop band of an acoustic double fishnet

Copyright © 2013 Acoustical Society of AmericaThe acoustic transmittance of two closely spaced solid plates, each perforated with a square array of cylindrical holes, exhibits a band of near-perfect acoustic attenuation originating from hybridization between a resonance in the gap separating the plates and pipe resonances in the holes. Displacement of one plate relative to the other, such that the holes are no longer aligned, or an increase in the plate separation leads to an increased center frequency of the stop band. This ability to easily tune the frequency of the stop band may prove advantageous.The authors acknowledge funding of ARJM by EPSRC and Sonardyne International

Charge-transfer dynamics at the dye-semiconductor interface of photocathodes for solar energy applications

This article describes a comparison between the photophysical properties of two charge-transfer dyes adsorbed onto NiO via two different binding moieties. Transient spectroscopy measurements suggest that the structure of the anchoring group affects both the rate of charge recombination between the dye and NiO surface and the rate of dye regeneration by an iodide/triiodide redox couple. This is consistent with the performance of the dyes in p-type dye sensitised solar cells. A key finding was that the recombination rate differed in presence of the redox couple. This has important implications on the study of electron transfer at dye|semiconductor interfaces for solar energy applications