Negotiating the British landscape

According to many accounts, a key paradigm for understanding art in Post WWII Britain is one of Englishness versus internationalism or abstraction versus realism . These terms have a rich inflection of meanings that have been subject to interrogation over the last few decades. Anwar Shemza came to Britain and practiced his art at a time when these competing claims were at their height. In a postcolonial reading entitled “Black Diaspora Artists in Britain: Three ‘Moments’ in Post-War Britain” Stuart Hall recently used David Scott’s framework of a ‘problem space’, that is discursively defined through questions, tensions and conjunctures, that couched the entry of what he describes as first waive British commonwealth artists into critical visibility in Britain. This can be characterized in part by the reviews of WG Archer and GM Butcher, both supporters of Shemza and prominent critics of the period. Hall includes Shemza in this framework that defines the work and his aspirations as constituted through the tensions of what was perceived to be anti-colonialist aims of modernism through universalism and the ‘nativist’ current in anti-colonial nationalism . This text will focus particularly on the problematic of Landscape as a ‘problem space’ of vernacular and modernism, over here and over there. The aim is not to define Shemza within the tradition of English landscape nor to exclude him but to position him within a discursive field of landscape and modernism in mid twentieth Century art.

G6f-like is an ITAM-containing collagen receptor in thrombocytes

Collagen activates mammalian platelets through a complex of the immunoglobulin (Ig) receptor GPVI and the Fc receptor γ-chain, which has an immunoreceptor tyrosine-based activation motif (ITAM). Cross-linking of GPVI mediates activation through the sequential activation of Src and Syk family kinases and activation of PLCγ2. Nucleated thrombocytes in fish are activated by collagen but lack an ortholog of GPVI. In this study we show that collagen activates trout thrombocytes in whole blood and under flow conditions through a Src kinase driven pathway. We identify the Ig receptor G6f-like as a collagen receptor and demonstrate in a cell line assay that it signals through its cytoplasmic ITAM. Using a morpholino for in vivo knock-down of G6f-like levels in zebrafish, we observed a marked delay or absence of occlusion of the venous and arterial systems in response to laser injury. Thus, G6f-like is a physiologically relevant collagen receptor in fish thrombocytes which signals through the same ITAM-based signalling pathway as mammalian GPVI, providing a novel example of convergent evolution.

Living the Revolution: urban communes & soviet socialism, 1917-1932

This book follows a revolutionary trend popular among young activists and would-be radicals after 1917, the formation of collective units of cohabitation and association known as 'urban communes'. In these spaces, activists tried to live what they understood as the 'socialist lifestyle', self-consciously putting Marxist and Bolshevik theories into practice. By telling the story of the urban communes, this book reveals how grand revolutionary ideals, such as collectivism, equality, proletarian ethics, and modern practice, were experienced, understood, and appropriated on a human level. This enables us to better understand the messy realities of the early Soviet state, showing how ideological beliefs and revolutionary contingencies actually came into being during this time.

Fractional quantum Hall effect in second subband of a 2DES

In the present paper we report on the experimental electron sheet density vs. magnetic field diagram for the magnetoresistance R(xx) of a two-dimensional electron system (2DES) with two occupied subbands. For magnetic fields above 9T, we found fractional quantum Hall levels centered around the filing factor v = 3/2 in both the two occupied electric subbands. We focused specially on the fractional levels of the second subband, whose experimental values of the magnetic field B of their minima do not obey a periodicity law in 1/|B-B(c)|, where B(c) is the critical field at the filling factor v = 3/2, and we explain this fact entirely in the framework of the composite fermions theory. We use a simple theoretical model to give a possible explanation for the fact. Copyright (c) EPLA, 2011

Reentrant quantum Hall effect in bilayer system at high filling factors

We report on the measurements of the quantum Hall effect states in double quantum well structures at the filling factors v = 4N + 1 and 4N + 3, where N is the Landau index number, in the presence of the in-plane magnetic field. The quantum Hall states at these filling factors vanish and reappear several times. Repeated reentrance of the transport gap occurs due to the periodic vanishing of the tunneling amplitude in the presence of the in-plane field. When the gap vanishes, the transport becomes anisotropic. The anisotropy persist at half-odd filling factors, when bilayer quantum Hall states are recovered with increase of the tilt angle. (C) 2007 Elsevier B.V. All rights reserved.

QUANTUM HALL FERROMAGNET IN A DOUBLE WELL WITH VANISHING g-FACTOR.

We have studied the quantum Hall effect in Al(x)Ga(1-x)As-double well structure with vanishing g-factor. We determined the density-magnetic field n(s) - B diagrams for the longitudinal resistance R(xx). In spite of the fact that the n(s) - B diagram for conventional GaAs double wells shows a striking similarity with the theory, we observed the strong difference between these diagrams for double wells with vanishing g-factor. We argue that the electron-electron interaction is responsible for unusual behavior of the Landau levels in such a system.

Spin Hall Effect in Symmetric Wells with Two Subbands

We investigate the spin Hall conductivity sigma (xy) (z) of a clean 2D electron gas formed in a two-subband well. We determine sigma (xy) (z) as arising from the inter-subband induced spin-orbit (SO) coupling eta (Calsaverini et al., Phys. Rev. B 78:155313, 2008) via a linear-response approach due to Rashba. By self-consistently calculating eta for realistic wells, we find that sigma (xy) (z) presents a non-monotonic (and non-universal) behavior and a sign change as the Fermi energy varies between the subband edges. Although our sigma (xy) (z) is very small (i.e., a parts per thousand(a)`` e/4 pi aEuro(3)), it is non-zero as opposed to linear-in-k SO models.

PL spectroscopy of Fermi electrons in regime of the quantum Hall effect

The influence of the interlayer coupling on formation of the quantized Hall phase at the filling factor v = 2 was studied in the multilayer GaAs/AlGaAs heterostructures The disorder broaden Gaussian photoluminescence line due to the localized electrons was found in the quantized Hall phase of the isolated multi-quantum well structure On the other hand. the quantized Hall phase of the weakly-coupled multilayers emitted an asymmetrical line similar to that one observed in the metallic electron systems. We demonstrated that the observed asymmetry indicates a formation of the Fermi Surface in the quantized Hall phase of the multilayer electron system due to the interlayer peicolation. A sharp decrease of the single-particle scattering time associated with the extended states oil the Fermi surface was observed at the filling factor v = 2. (C) 2009 Elsevier B.V All rights reserved

Influence of interlayer tunneling on the quantized Hall phases in intentionally disordered multilayer structures

Stability of the quantized Hall phases is studied in weakly coupled multilayers as a function of the interlayer correlations controlled by the interlayer tunneling and by the random variation of the well thicknesses. A strong enough interlayer disorder destroys the symmetry responsible for the quantization of the Hall conductivity, resulting in the breakdown of the quantum Hall effect. A clear difference between the dimensionalities of the metallic and insulating quantum Hall phases is demonstrated. The sharpness of the quantized Hall steps obtained in the coupled multilayers with different degrees of randomization was found consistent with the calculated interlayer tunneling energies. The observed width of the transition between the quantized Hall states in random multilayers is explained in terms of the local fluctuations of the electron density.

Compressibility of electron liquid in the quantized Hall phase of GaAs/AlGaAs multi-layers

Magneto-capacitance was studied in narrow miniband GaAs/AlGaAs superlattices where quasi-two dimensional electrons revealed the integer quantum Hall effect. The interwell tunneling was shown to reduce the effect of the quantization of the density of states on the capacitance of the superlattices. In such case the minimum of the capacitance observed at the filling factor nu = 2 was attributed to the decrease of the electron compressibility due to the formation of the incompressible quantized Hall phase. In accord with the theory this phase was found strongly inhomogeneous. The incompressible fraction of the quantized Hall phase was demonstrated to rapidly disappear with the increasing temperature. (C) 2008 Elsevier B.V. All rights reserved.

Spectroscopic evidence of extended states in quantized Hall phase of weakly coupled GaAs/AlGaAs multi-layers

The influence of the interlayer coupling on formation of the quantized Hall conductor phase at the filling factor v = 2 was studied in the multi-layer GaAs/AlGaAs heterostructures. The disorder broadened Gaussian photoluminescence line due to the localized electrons was found in the quantized Hall phase of the isolated multi-quantum well structure. On the other hand, the quantized Hall phase of the weakly coupled multi-layers emitted an unexpected asymmetrical line similar to that one observed in the metallic electron systems. We demonstrated that the observed asymmetry is caused by a partial population of the extended electron states formed in the quantized Hall conductor phase due to the interlayer percolation. A sharp decrease of the single-particle scattering time associated with these extended states was observed at the filling factor v = 2. (c) 2007 Elsevier B.V. All rights reserved.

Vi och de andra : En studie av hur män och kvinnor med invandrarbakgrund framställs i svenska invandrarfilmer från år 2000

Syftet med den här uppsatsen har varit att visa hur män och kvinnor med invandrarbakgrund framställs i svenska så kallade invandrarfilmer från år 2000. De frågeställningar jag arbetat utifrån är: Hur porträtteras män samt kvinnor med invandrarbakgrund i de svenska ”invandrarfilmerna” från år 2000? Vilka stereotyper kan man tänkas finna? Har det skett någon förändring i hur män och kvinnor med invandrarbakgrund porträtterats i svensk film? För att få svar på frågorna har jag genomfört textanalyser av fem filmer - Jalla! Jalla! av Josef Fares, Före stormen av Reza Parsa, Vingar av glas av Reza Bagher, Det nya landet av Geir Hansteen Jörgensen samt Bastarderna i paradiset av Luis R. Vera - utifrån teorier om genus, ”ras” och etnicitet. Teorierna har jag hämtat från bland andra Anthony Giddens, Yvonne Hirdman, Laura Mulvey, Paulina de los Reyes, Charles Ramírez Berg och Stuart Hall. Dessutom har jag jämfört filmerna med Rochelle Wrights studie av svenska filmer med invandrarkaraktärer från 1970-1990-talet för att se om det har skett någon förändring i gestaltningen av personer från andra delar av världen. Analyserna har visat att trots att filmerna från år 2000 är regisserade av personer som själva har invandrarbakgrund, så gestaltas invandrarna generellt sätt utifrån grova stereotyper. Det mest framträdande dragen i stereotyperna är att dessa, oavsett kön, gestaltas som avvikande samt som en del i en familjegrupp. Invandrarmän framställs som barnsliga, våldsbenägna, aggressiva samt som förtryckande gentemot kvinnor. Invandrarkvinnor framställs som konstiga, maktlösa, isolerade, okunniga offer samt som underordnad gentemot män. De filmer som delvis avviker, och som därmed uppvisar förändringar jämfört med tidigare filmer, är Före stormen och Det nya landet. I Före stormen har man nämligen kastat om könsrollerna. Invandrarmannen är underordnad gentemot kvinnorna, samtidigt som han gestaltas som en helt vanlig individ. I Det nya landet gestaltar man invandrarmän på ett mer positivt sätt. Fastän dessa gestaltas som grova stereotyper, revideras de på ett påtagligt sätt. De omarbetas genom att man tillskriver invandrare fördjupade egenskaper som är oförutsägbara under filmens gång. Vidare attribuerar man dem en logik som bidrar till att åskådarna nu får tillgång till att se på invandrarmän ur ett annat perspektiv, bortom den ensidiga stereotypbilden.

Teoria das mediações e estudos culturais: convergências e perspectivas

Este artigo procura resgatar, brevemente, o momento histórico em que a Teoria das Mediações e os Estudos Culturais desenvolveram-se e as categorias que construíram para compreender os processos de produção de sentido em um mundo no qual a comunicação mediada fez-se, cada vez, mais presente. Procura-se tratar, aqui, das convergências na orientação da pesquisa baseada nos trabalhos de Raymond Williams e as novas gerações dos Estudos Culturais (como Stuart Hall, Roger Silverstone, David Morley) com relação aos trabalhos de Jésus Martín-Barbero, Néstor Canclini e Guilhermo Orozco. Essas convergências e perspectivas precisam ser avaliadas, pois devem compor o referencial teórico de uma série de pesquisas com a produção de sentido em novos ambientes integrados às novas tecnologias. Tecnologias que possibilitam uma maior ou menor intervenção direta do usuário, cada vez mais, por meio de redes sem fio, e que podem tirar do espaço doméstico a primazia do contexto de fruição, usos e apropriações.