H.D. et le groupe Pool : des avant-gardes littéraires au cinéma " visionnaire "

Résumé Cet essai retrace l'implication de l'écrivaine américaine Hilda Doolittle (qui signe H. D.) au sein du groupe Pool (1927-1933), dont les activités sont centrées sur le cinéma. Nous mettons ainsi en évidence les points de convergence entre les théories de l'image dans les mouvements littéraires imagistes, vorticistes ou encore objectivistes, et les débats qui portent sur les moyens d'expression et la fonction du film dans les milieux émergents de la cinéphilie. H. D., dont les premiers poèmes ont été médiatisés par Ezra Pound et la revue Poetry, transpose son expérience de l'espace littéraire dans le contexte du cinéma. La logique du long-métrage Borderline (Kenneth Macpherson, Suisse, 1930) et les points de vue qui s'expriment dans la revue Close Up (juillet 1927-décembre 1933) sont surdéterminés par le mythe expressif d'un renouvellement de l'écriture idéogrammatique, traversant la poésie d'avant-garde anglo-saxonne depuis les années 1910. L'enjeu de cette recherche est double. D'une part, nous soutenons qu'une dynamique cinématographique sous-tend les manifestes et les poèmes publiés dans le contexte des premières avant-gardes historiques anglo-américaines. En un sens, les recherches sur l'objectivation des images et la fragmentation du rythme trouvent un point de résolution dans le caractère indiciel des photogrammes et les procédés du montage discontinu. D'autre part, nous démontrons que les expérimentations sur le vers libre et les formes poétiques ouvertes conditionnent les réflexions du groupe Pool sur le cinéma et leur pratique filmique. Nous analysons dans le détail deux «textes » : nous rapportons Borderline au genre surréaliste du scénario intournable, et nous relisons le dernier poème de H. D. en regard des théories du montage d'Eisenstein. Le modèle princeps du hiéroglyphe, qui est convoqué par Eisenstein et par Pound, mais que H. D. et Freud s'approprient également, constitue le fil rouge qui permet de nouer ces différents liens.

Iterative image reconstruction techniques: cardiothoracic computed tomography applications.

Iterative image reconstruction algorithms provide significant improvements over traditional filtered back projection in computed tomography (CT). Clinically available through recent advances in modern CT technology, iterative reconstruction enhances image quality through cyclical image calculation, suppressing image noise and artifacts, particularly blooming artifacts. The advantages of iterative reconstruction are apparent in traditionally challenging cases-for example, in obese patients, those with significant artery calcification, or those with coronary artery stents. In addition, as clinical use of CT has grown, so have concerns over ionizing radiation associated with CT examinations. Through noise reduction, iterative reconstruction has been shown to permit radiation dose reduction while preserving diagnostic image quality. This approach is becoming increasingly attractive as the routine use of CT for pediatric and repeated follow-up evaluation grows ever more common. Cardiovascular CT in particular, with its focus on detailed structural and functional analyses, stands to benefit greatly from the promising iterative solutions that are readily available.

Image-Derived Input Function from the Vena Cava for 18F-FDG PET Studies in Rats and Mice.

Measurement of arterial input function is a restrictive aspect for quantitative (18)F-FDG PET studies in rodents because of their small total blood volume and the related difficulties in withdrawing blood.

A 2D/3D image analysis system to track fluorescently labeled structures in rod-shaped cells: application to measure spindle pole asymmetry during mitosis.

BACKGROUND: The yeast Schizosaccharomyces pombe is frequently used as a model for studying the cell cycle. The cells are rod-shaped and divide by medial fission. The process of cell division, or cytokinesis, is controlled by a network of signaling proteins called the Septation Initiation Network (SIN); SIN proteins associate with the SPBs during nuclear division (mitosis). Some SIN proteins associate with both SPBs early in mitosis, and then display strongly asymmetric signal intensity at the SPBs in late mitosis, just before cytokinesis. This asymmetry is thought to be important for correct regulation of SIN signaling, and coordination of cytokinesis and mitosis. In order to study the dynamics of organelles or large protein complexes such as the spindle pole body (SPB), which have been labeled with a fluorescent protein tag in living cells, a number of the image analysis problems must be solved; the cell outline must be detected automatically, and the position and signal intensity associated with the structures of interest within the cell must be determined. RESULTS: We present a new 2D and 3D image analysis system that permits versatile and robust analysis of motile, fluorescently labeled structures in rod-shaped cells. We have designed an image analysis system that we have implemented as a user-friendly software package allowing the fast and robust image-analysis of large numbers of rod-shaped cells. We have developed new robust algorithms, which we combined with existing methodologies to facilitate fast and accurate analysis. Our software permits the detection and segmentation of rod-shaped cells in either static or dynamic (i.e. time lapse) multi-channel images. It enables tracking of two structures (for example SPBs) in two different image channels. For 2D or 3D static images, the locations of the structures are identified, and then intensity values are extracted together with several quantitative parameters, such as length, width, cell orientation, background fluorescence and the distance between the structures of interest. Furthermore, two kinds of kymographs of the tracked structures can be established, one representing the migration with respect to their relative position, the other representing their individual trajectories inside the cell. This software package, called "RodCellJ", allowed us to analyze a large number of S. pombe cells to understand the rules that govern SIN protein asymmetry. CONCLUSIONS: "RodCell" is freely available to the community as a package of several ImageJ plugins to simultaneously analyze the behavior of a large number of rod-shaped cells in an extensive manner. The integration of different image-processing techniques in a single package, as well as the development of novel algorithms does not only allow to speed up the analysis with respect to the usage of existing tools, but also accounts for higher accuracy. Its utility was demonstrated on both 2D and 3D static and dynamic images to study the septation initiation network of the yeast Schizosaccharomyces pombe. More generally, it can be used in any kind of biological context where fluorescent-protein labeled structures need to be analyzed in rod-shaped cells. AVAILABILITY: RodCellJ is freely available under http://bigwww.epfl.ch/algorithms.html, (after acceptance of the publication).

Image quality assessment in digital mammography: part I. Technical characterization of the systems.

In many European countries, image quality for digital x-ray systems used in screening mammography is currently specified using a threshold-detail detectability method. This is a two-part study that proposes an alternative method based on calculated detectability for a model observer: the first part of the work presents a characterization of the systems. Eleven digital mammography systems were included in the study; four computed radiography (CR) systems, and a group of seven digital radiography (DR) detectors, composed of three amorphous selenium-based detectors, three caesium iodide scintillator systems and a silicon wafer-based photon counting system. The technical parameters assessed included the system response curve, detector uniformity error, pre-sampling modulation transfer function (MTF), normalized noise power spectrum (NNPS) and detective quantum efficiency (DQE). Approximate quantum noise limited exposure range was examined using a separation of noise sources based upon standard deviation. Noise separation showed that electronic noise was the dominant noise at low detector air kerma for three systems; the remaining systems showed quantum noise limited behaviour between 12.5 and 380 µGy. Greater variation in detector MTF was found for the DR group compared to the CR systems; MTF at 5 mm(-1) varied from 0.08 to 0.23 for the CR detectors against a range of 0.16-0.64 for the DR units. The needle CR detector had a higher MTF, lower NNPS and higher DQE at 5 mm(-1) than the powder CR phosphors. DQE at 5 mm(-1) ranged from 0.02 to 0.20 for the CR systems, while DQE at 5 mm(-1) for the DR group ranged from 0.04 to 0.41, indicating higher DQE for the DR detectors and needle CR system than for the powder CR phosphor systems. The technical evaluation section of the study showed that the digital mammography systems were well set up and exhibiting typical performance for the detector technology employed in the respective systems.

Le devenir féminin transgenre : une étude qualitative et réflexive sur le genre, la corporéité et la subjectivité sexuelle

RésuméCette thèse en psychologie qualitative et critique de la santé propose un éclairage, sur la subjectivité transgenre, différent des modèles dominants en clinique. Les nosologies de type DSM et de la psychiatrie dominante focalisent sur la seule question de la transition transsexuelle, elles utilisent la sexualité comme outil dans les diagnostics différentiels permettant d'effectuer le gatekeeping de la transition médicalisée du genre. Elles sont décrites comme un dispositif de médicalisation du genre, induisant des pratiques maltraitantes. Une méthodologie qualitative inspirée de la théorie ancrée ainsi que de l'analyse réflexive est utilisée. Un échantillon de 15 personnes représentant la diversité des personnes transgenres FtM a été recruté. Les données provenant d'entrevues non directives sont analysées dans une perspective verticale et horizontale. Les résultats soulignent l'inadéquation des typologies cliniques, de la place qui est donnée à la sexualité dans les procédures diagnostiques et de l'opposition qu'elles construisent entre identité (de genre) et sexualité. Ils plaident pour une vision deleuzienne de type nomade, incarnée et sexuée de la subjectivité transgenre.AbstractThe broad of this study in critical health psychology is to build an understanding of transgender subjectivity which contrast with dominant clinical models. DSM nosology types and dominant psychiatry have traditionally focused only on transsexual transitioning. They use sexuality as a diagnostic tool to address the gatekeeping of the medical transition. These practices have been described as medicalization of gender, inducing mistreatment. A qualitative methodology mixing grounded theory and reflexivity has been used. A sample of 15 persons has been recruited to represent transgender FtM diversity. Data were collected through in-depth interview and analysed case by case and by themes. Results show that dominant clinical typologies of TG are inappropriate, as well as the way sexuality is used in this practices and the opposition between (gender) identity and sexuality. We propose a deleuzian concept of becoming and multiplicity to understand transgender subjectivity.

Image en fluorescence en endoscopie: contribution dans la prise en charge des tumeurs de vessie [Fluorescence guided endoscopy: improvement in the management of bladder cancer].

White-light cystoscopy and cytology are the standard tools to diagnose bladder cancer. White-light cystoscopy is excellent to detect macroscopic exophytic tumors, but its sensitivity is poor for flat tumors such as carcinoma in situ. Use of fluorescence cystoscopy during transurethral bladder resection improve tumor detection, particulary for carcinoma in situ. Fluorescence cystoscopy reduce residual tumor rate, especially for voluminous and multifocal tumors with consecutive lower recurrence. Fluorescence is now recommended to diagnose and treat bladder cancer.

Is there an advantage to be gained from adding digital image cytometry of brush cytology to a standard biopsy protocol in patients with Barrett's esophagus?

BACKGROUND AND STUDY AIMS: The current gold standard in Barrett's esophagus monitoring consists of four-quadrant biopsies every 1-2 cm in accordance with the Seattle protocol. Adding brush cytology processed by digital image cytometry (DICM) may further increase the detection of patients with Barrett's esophagus who are at risk of neoplasia. The aim of the present study was to assess the additional diagnostic value and accuracy of DICM when added to the standard histological analysis in a cross-sectional multicenter study of patients with Barrett's esophagus in Switzerland. METHODS: One hundred sixty-four patients with Barrett's esophagus underwent 239 endoscopies with biopsy and brush cytology. DICM was carried out on 239 cytology specimens. Measures of the test accuracy of DICM (relative risk, sensitivity, specificity, likelihood ratios) were obtained by dichotomizing the histopathology results (high-grade dysplasia or adenocarcinoma vs. all others) and DICM results (aneuploidy/intermediate pattern vs. diploidy). RESULTS: DICM revealed diploidy in 83% of 239 endoscopies, an intermediate pattern in 8.8%, and aneuploidy in 8.4%. An intermediate DICM result carried a relative risk (RR) of 12 and aneuploidy a RR of 27 for high-grade dysplasia/adenocarcinoma. Adding DICM to the standard biopsy protocol, a pathological cytometry result (aneuploid or intermediate) was found in 25 of 239 endoscopies (11%; 18 patients) with low-risk histology (no high-grade dysplasia or adenocarcinoma). During follow-up of 14 of these 18 patients, histological deterioration was seen in 3 (21%). CONCLUSION: DICM from brush cytology may add important information to a standard biopsy protocol by identifying a subgroup of BE-patients with high-risk cellular abnormalities.