« Spirit of the dead, rise up! […] and claim your story ». Représentation de l’esclavage et esthétique de la résistance dans Sankofa (Haile Gerima, 1993)

Le cinéaste éthiopien indépendant Haile Gerima fait partie du groupe de réalisateurs noirs américains baptisé LA Rebellion. Parallèlement à sa carrière d’universitaire, Gerima a réalisé plusieurs films traitant de divers aspects de l’expérience noire américaine et diasporique. C’est avec Sankofa (1993) qu’il connut son premier grand succès. Traitant de la résistance à l’oppression par le biais de la mythologie akan – en particulier l’oiseau sankofa, symbole de la nécessité pour toute personne de se tourner vers son passé pour appréhender l’avenir –, le film définit une politique et une esthétique de la résistance à l’esclavage. Sankofa a essentiellement été analysé dans sa dimension politique, idéologique et historique. Cet article se penche sur sa dimension esthétique et sémiotique, élément à part entière du discours idéologique sur la résistance à l’esclavage.Haile Gerima, an independent Ethiopian filmmaker who belonged to the LA Rebellion film movement, directed films which dealt with various aspects of the African American and black diasporic experience. Sankofa (1993) was his first important critical and commercial success. The film used Akan mythology—in particular the sankofa bird symbolizing the need for every person to turn to the past in order to face their future—to broach the issue of resistance to oppression. In Sankofa, Gerima developed a politics and aesthetic of resistance. While the film’s political, ideological, and historical dimensions have been extensively analyzed, this essay focuses on its aesthetic dimension, which is the cornerstone of its ideological discourse on resistance to slavery

Cell cycle genes regulate vestigial and scalloped to ensure normal proliferation in the wing disc of Drosophila melanogaster.

In Drosophila, the Vestigial-Scalloped (VG-SD) dimeric transcription factor is required for wing cell identity and proliferation. Previous results have shown that VG-SD controls expression of the cell cycle positive regulator dE2F1 during wing development. Since wing disc growth is a homeostatic process, we investigated the possibility that genes involved in cell cycle progression regulate vg and sd expression in feedback loops. We focused our experiments on two major regulators of cell cycle progression: dE2F1 and the antagonist dacapo (dap). Our results reinforce the idea that VG/SD stoichiometry is critical for correct development and that an excess in SD over VG disrupts wing growth. We reveal that transcriptional activity of VG-SD and the VG/SD ratio are both modulated upon down-expression of cell cycle genes. We also detected a dap-induced sd upregulation that disrupts wing growth. Moreover, we observed a rescue of a vg hypomorphic mutant phenotype by dE2F1 that is concomitant with vg and sd induction. This regulation of the VG-SD activity by dE2F1 is dependent on the vg genetic background. Our results support the hypothesis that cell cycle genes fine-tune wing growth and cell proliferation, in part, through control of the VG/SD stoichiometry and activity. This points to a homeostatic feedback regulation between proliferation regulators and the VG-SD wing selector

Notch pathway repression by vestigial is required to promote indirect flight muscle differentiation in Drosophila melanogaster

AbstractDrosophila dorsal longitudinal muscles develop during metamorphosis by fusion of myoblasts with larval templates. It has been shown that both vestigial and Notch are crucial for correct formation of these muscles. We investigated the relationship between vestigial and the Notch pathway during this process. Using Enhancer of Split Region Transcript m6 gene expression as a reporter of Notch pathway activity, we were able to demonstrate that this pathway is only active in myoblasts. Moreover, close examination of the cellular location of several of the main actors of the N pathway (Notch, Delta, neuralized, Serrate, Mind bomb1 and fringe) during dorsal longitudinal muscle development enabled us to find that Notch receptor can play multiple roles in adult myogenesis. We report that the locations of the two Notch ligands (Delta and Serrate) are different. Interestingly, we found that fringe, which encodes a glycosyltransferase that modifies the affinity of the Notch receptor for its ligands, is expressed in muscle fibers and in a subset of myoblasts. In addition, we demonstrate that fringe expression is essential for Notch pathway inhibition and muscle differentiation. Lastly, we report that, in vestigial mutants, fringe expression is lost, and when fringe is overexpressed, a significant rescue of indirect flight muscle degeneration is obtained. Altogether, our data show that a vestigial-differentiating function is achieved through the inhibition of the Notch pathway

Visualizing Consumer Culture, Commodifying Visual Culture : Spectacles of the Consumer Society

In London, from May to October 1851, countless shoppers and strollers walked the aisles of the Crystal Palace, specially designed and built to house the Great Exhibition of the Works of Industry of All Nations, to admire the displays of commodities which had been mostly produced in Great Britain and its colonies—representing more than half of the exhibited consumer goods. The Crystal Palace was an architectural feat, an awe-inspiring structure of glass and iron ; as for the Great Exhibition, ..

Goos-Haenchen induced vector eigenmodes in a dome cavity

We demonstrate numerically calculated electromagnetic eigenmodes of a 3D dome cavity resonator that owe their shape and character entirely to the Goos-Haenchen effect. The V-shaped modes, which have purely TE or TM polarization, are well described by a 2D billiard map with the Goos-Haenchen shift included. A phase space plot of this augmented billiard map reveals a saddle-node bifurcation; the stable periodic orbit that is created in the bifurcation corresponds to the numerically calculated eigenmode, dictating the angle of its "V". A transition from a fundamental Gaussian to a TM V mode has been observed as the cavity is lengthened to become nearly hemispherical.Comment: 4 pages, 4 figure

Virtual enactment effect on memory in young and aged populations: a systematic review

Background: Spatial cognition is a critical aspect of episodic memory, as it provides the scaffold for events and enables successful retrieval. Virtual enactment (sensorimotor and cognitive interaction) by means of input devices within virtual environments provides an excellent opportunity to enhance encoding and to support memory retrieval with useful traces in the brain compared to passive observation. Methods: We conducted a systematic review with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines concerning the virtual enactment effect on spatial and episodic memory in young and aged populations. We aim at giving guidelines for virtual enactment studies, especially in the context of aging, where spatial and episodic memory decline. Results: Our findings reveal a positive effect on spatial and episodic memory in the young population and promising outcomes in aging. Several cognitive factors (e.g., executive function, decision-making, and visual components) mediate memory performances. Findings should be taken into account for future interventions in aging. Conclusions: The present review sheds light on the key role of the sensorimotor and cognitive systems for memory rehabilitation by means of a more ecological tool such as virtual reality and stresses the importance of the body for cognition, endorsing the view of an embodied mind

Aging and posture in the memory of manipulable objects

Thirty healthy elderly participants (mean age = 77.3) learned the names of manipulable and nonmanipulable objects while adopting a control posture (hands in front of them) or an interfering posture (holding their hands behind their back). Results on a recall task showed a postural interference (PI) effect, with the interfering posture reducing the memory of manipulable objects, but not of nonmanipulable ones. The effect was similar to the Postural Interference effect previously observed in young adults, although with a lower performance. These results call into question the embodied theory hypothesis that the deterioration of memory in aging is related to the decline of the sensorimotor system

Integration of differentiation signals during indirect flight muscle formation by a novel enhancer of Drosophila vestigial gene

AbstractThe gene vestigial (vg) plays a key role in indirect flight muscle (IFM) development. We show here that vg is controlled by the Notch anti-myogenic signaling pathway in myoblasts and is regulated by a novel 822 bp enhancer during IFM differentiation. Interestingly, this muscle enhancer is activated in developing fibers and in a small number of myoblasts before the fusion of myoblasts with the developing muscle fibers. Moreover, we show that this enhancer is activated by Drosophila Myocyte enhancing factor 2 (MEF2), Scalloped (SD) and VG but repressed by Twist, demonstrating a sensitivity to differentiation in vivo. In vitro experiments reveal that SD can directly bind this enhancer and MEF2 can physically interact with both SD and TWI. Cumulatively, our data reveal the interplay between different myogenic factors responsible for the expression of an enhancer activated during muscle differentiation

in vivo analysis of Drosophila deoxyribonucleoside kinase function in cell cycle, cell survival and anti-cancer drugs resistance.

in vitro studies have shown that Drosophila melanogaster has a highly efficient single deoxyribonucleoside kinase (dNK) multisubstrate enzyme. dNK is related to the mammalian Thymidine Kinase 2 (TK2) group involved in the nucleotide synthesis salvage pathway. To study the dNK function in vivo, we constructed transgenic Drosophila strains and impaired the nucleotide de novo synthesis pathway, using antifolates such as aminopterin. Our results show that dNK overexpression rescues both cell death and cell cycle arrest triggered by this anti-cancer drug, and confers global resistance on the fly. Moreover, we show that fly viability and growth depend on the exquisite ratio between dNK expression and its substrate thymidine (dT) in the medium, and that increased dT concentrations trigger apoptosis and a decrease in body mass when dNK is mis-expressed. Finally, dNK expression, unlike that of TK2, is cell cycle dependent and under the control of CyclinE and the dE2F1 transcription factor involved in the G1/S transition. dNK is therefore functionally more closely related to mammalian TK1 than to TK2. This strongly suggest that dNK plays a role in cell proliferation in physiological conditions

When the South/ern meets the West/ern

As shown by Quentin Tarantino’s latest film,Django Unchained (2012), compared to westerns, motion pictures on the American South are often presented as films of a “bad genre”. However, like the movie scenarios on the Far West, the great narratives and quintessential representations of the Deep South have also profoundly affected the vision we have of American history and culture. Why, then, did we have to wait until the release of Tarantino’s parodic and provocative western-soaked southern (or vice versa) to realize to what extent the codes, myths, motifs and typologies of the western genre can interact and overlap with the generic traits of the southern? This and related questions will be debated by American, British and French specialists of American cinema at the April 2013 international symposium “When the West/ern meets the South/ern” at the University of Versailles Saint-Quentin-en-Yvelines. Transatlantic and transdisciplinary, the encounter between film and literary studies, history and politics will constitute a major step towards the creation of an international network to enhance further explorations of this fascinating interdisciplinary object of study marked by the idea of “splitting”, as well as by notions of “crossing” and “hybridization”