Imagerie de la valve aortique en IRM.

Messages à retenir: Les séquences de ciné MR sont utiles pour rechercher une bicuspidie. Les séquences en contraste de phase permettent de mesurer les vitesses et flux transvalvulaires. La fraction de régurgitation est corrélée à la sévérité de l'insuffisance aortique. Une planimétrie peut être effectuée sur les séquences de ciné MR ou de flux. Résumé: L'étude de la valve aortique en IRM nécessite un placement rigoureux des plans de coupes à partir de 2 incidences orthogonales passant par la chambre de chasse. Les séquences de ciné IRM permettent une analyse dynamique de l'ouverture de la valve et sont utiles pour rechercher une bicuspidie et une dilatation de l'aorte. Leur sensibilité au flux turbulents est relativement faible vu leur TE court, à l'inverse des séquences en écho de gradient à TE long. Les séquences de ciné MR permettent également de calculer les volumes ventriculaires gauches et la fraction d'éjection, paramètres importants dans le traitement. Les séquences en contraste permettent de mesurer la vitesse trans-valvulaire et de calculer le volume éjecté dans l'aorte et le volume régurgité dans le ventricule gauche. Elles peuvent être réalisées dans le plan du flux ou au travers du plan. Il est important de régler correctement la vitesse de codage maximale afin d'éviter des erreurs de codage de vitesse (phénomène d'"aliasing"). Dans le cadre d'une insuffisance aortique, le ratio volume régurgité / volume éjecté, appelé fraction de régurgitation, est relié à la sévérité de la valvulopathie. L'IRM peut également permettre de réaliser une planimétrie de l'orifice valvulaire aortique.

Iowa Developments, Volume 16, Number 3

Business news from the Iowa Department of Economic Development

Volume expansion enhances plasma endothelin-1.

We hypothesized that acute volume expansion by saline infusion triggers the release of endothelin-1. Bolus intravenous saline infusion (8 mL/min) in six groups of conscious Wistar rats and spontaneously hypertensive rats did not change mean arterial pressure or heart rate (n = 8 to 12). At 1 min after infusion, the plasma endothelin-1 level was significantly increased in Wistar rats and in spontaneously hypertensive rats by 42% and 61%, respectively (unpaired data). In 12 Wistar rats, the endothelin-1 level increased from 0.68 +/- 0.13 to 1.19 +/- 0.17 fmol/mL (mean +/- SEM, P <.0001, paired data). Thus, acute volume load by rapid saline infusion increases plasma endothelin-1 levels. Vasoconstriction induced by endothelin-1 may counteract enhanced circumferential stretch created by volume expansion.

Physical considerations on discrepancies in target volume delineation.

BACKGROUND AND PURPOSE: To compare the delineations and interpretations of target volumes by physicians in different radio-oncology centers. MATERIALS AND METHODS: Eleven Swiss radio-oncology centers delineated volumes according to ICRU 50 recommendations for one prostate and one head and neck case. In order to evaluate the consistency of the volume delineations, the following parameters were determined: 1) the target volumes (GTV, CTV and manually expanded PTV) and their extensions in the three main axes and 2) the correlation of the volume delineated by each pair of centers using the ratio of the intersection to the union (called proximity index). RESULTS: The delineated prostate volume was 105+/-55cm(3) for the CTV and 218+/-44cm(3) for the PTV. The delineated head and neck volume was 46+/-15cm(3) for the GTV, 327+/-154cm(3) for the CTV and 528+/-106cm(3) for the PTV. The mean proximity index for the prostate case was 0.50+/-0.13 for the CTV and 0.57+/-0.11 for the PTV. The proximity index for the head and neck case was 0.45+/-0.09 for the GTV, 0.42+/-0.13 for the CTV and 0.59+/-0.06 for the PTV. CONCLUSIONS: Large discrepancies between all the delineated target volumes were observed. There was an inverse relationship between the CTV volume and the margin between CTV and PTV, leading to less discrepancies in the PTV than is the CTV delineations. There was more spread in the sagittal and frontal planes due to CT pixel anisotropy, which suggests that radiation oncologists should delineate the target volumes not only in the transverse plane, but also in the sagittal and frontal planes to improve the delineation by allowing a consistency check.

Iowa Developments, January 2008, Volume 12, Number 1

Business news from the Iowa Department of Economic Development

Le juge en droit européen et international = The Judge in European and International Law

Le juge et son rôle ont été thématisés abondamment en théorie du droit, mais toujours sous l'angle du droit et du juge internes. On pensera ainsi aux questions des rapports entre justice et politique ou démocratie, ou encore au rôle créateur de droit du juge en cas de lacune juridique et à la légitimité du droit dit prétorien. Pour autant que l'on considère qu'il s'agisse bien d'un juge, le juge international ou européen et sa fonction judiciaire posent des problèmes de même type certes bien que plus aigus, mais aussi des difficultés nouvelles auxquelles la théorie du droit n'a pas encore donné de réponses. Le présent ouvrage tente d'identifier ces difficultés théoriques propres au juge international ou européen et d'apporter des débuts de réponse. Fruit du sixième colloque doctoral de l'Ecole doctorale Fondements du droit européen et international et quatrième volume de la collection du même nom, il réunit des contributions en anglais et en français rédigées par des doctorants des universités suisses romandes et alémaniques et d'universités européennes partenaires, mais aussi d'intervenants externes invités aux différentes sessions du colloque.

Tour Iowa, Volume No. 7, Issue No. 2, Spring 2008

A periodic e-newsletter from the Iowa Tourism Office for group tour planners that focuses on "new, unusual, and just plain different" opportunities for group travelers.

EORTC-ROG expert opinion: radiotherapy volume and treatment guidelines for neoadjuvant radiation of adenocarcinomas of the gastroesophageal junction and the stomach.

PURPOSE: The Gastro-Intestinal Working Party of the EORTC Radiation Oncology Group (GIWP-ROG) developed guidelines for target volume definition in neoadjuvant radiation of adenocarcinomas of the gastroesophageal junction (GEJ) and the stomach. METHODS AND MATERIALS: Guidelines about the definition of the clinical target volume (CTV) are based on a systematic literature review of the location and frequency of local recurrences and lymph node involvement in adenocarcinomas of the GEJ and the stomach. Therefore, MEDLINE was searched up to August 2008. Guidelines concerning prescription, planning and treatment delivery are based on a consensus between the members of the GIWP-ROG. RESULTS: In order to support a curative resection of GEJ and gastric cancer, an individualized preoperative treatment volume based on tumour location has to include the primary tumour and the draining regional lymph nodes area. Therefore we recommend to use the 2nd English Edition of the Japanese Classification of Gastric Carcinoma of the Japanese Gastric Cancer Association which developed the concept of assigning tumours of the GEJ and the stomach to anatomically defined sub-sites corresponding respectively to a distinct lymphatic spread pattern. CONCLUSION: The GIWP-ROG defined guidelines for preoperative irradiation of adenocarcinomas of the GEJ and the stomach to reduce variability in the framework of future clinical trials.

Iowa Developments, May 2008, Volume 17, Number 3

Business News from the Iowa Department of Economic Development

Análisis empírico del comportamiento de los costes en las explotaciones agrícolas mediante datos de la red contable agraria nacional

In this article an empirical analyse of farming costs is performed withinthe frame of the activity based costing, employing a panel data set ofCatalan farms. One the main conclusions of the study is that there islimited association for transaction and farm costs, especially in indirectcosts. Direct and indirect costs are mainly driven by volume production.

Iowa Developments, Volume 17, Number 4

Business news from the Iowa Department of Economic Development

Iowa Developments, August 2008, Volume 17, Number 5

Business Development news from the Iowa Department of Economic Development

Iowa Developments, October 2008, Volume 17, Number 6

Business Development news from the Iowa Department of Economic Development

Hippocampal volume predicts fluid intelligence in musically trained people.

Recently, age-related hippocampal (HP) volume loss could be associated with a decrease in general fluid intelligence (gF). In the present study we investigated whether and how extensive musical training modulates human HP volume and gF performance. Previously, some studies demonstrated positive effects of musical training on higher cognitive functions such as learning and memory, associated with neural adaptations beyond the auditory domain. In order to detect possible associations between musical training and gF, we bilaterally segmented the HP formation and assessed the individual gF performance of people with different levels of musical expertise. Multiple regression analyses revealed that HP volume predicts gF in musicians but not in nonmusicians; in particular, bilaterally enhanced HP volume is associated with increased gF exclusively in musically trained people (amateurs and experts). This result suggests that musical training facilitates the recruitment of cognitive resources, which are essential for gF and linked to HP functioning. Musical training, even at a moderate level of intensity, can thus be considered as a potential strategy to decelerate age-related effects of cognitive decline. © 2013 Wiley Periodicals, Inc.

Experiments on substratum roughness, grainsize and volume influence on the motion and spreading of rock avalanches

The main objective of the research is to link granular physics with the modelling of rock avalanches. Laboratory experiments consist to find a convenient granular material, i.e. grainsize and physical behaviour, and testing it on simple slope geometry. When the appropriate sliding material is selected, we attempted to model the debris avalanche and the spreading on a slope with different substratum to understand the relationship between the volume and the reach angle, i.e. angle of the line joining the top of the scar and the end of the deposit. For a better understanding of the mass spreading, the deposits are scanned with a laser scanner. Datasets are compared to see how the grain size and volume influence a debris avalanche. The relationship between the roughness and grainsize of the substratum shows that the spreading of the sliding mass is increased when the roughness of the substratum starts to be equivalent or greater than the grainsize of the flowing mass. The runout distance displays a more complex relationship, because a long runout distance implies that grains are less spread. This means that if the substratum is too rough the distance diminishes, as well if it is too smooth because the effect on the apparent friction decreases. Up to now our findings do not permit to validate any previous model (Melosh, 1987; Bagnold 1956).