Direct simulation of interface dynamics: linking capillary pressure, interfacial area and surface energy

We perform direct numerical simulations of drainage by solving Navier- Stokes equations in the pore space and employing the Volume Of Fluid (VOF) method to track the evolution of the fluid-fluid interface. After demonstrating that the method is able to deal with large viscosity contrasts and to model the transition from stable flow to viscous fingering, we focus on the definition of macroscopic capillary pressure. When the fluids are at rest, the difference between inlet and outlet pressures and the difference between the intrinsic phase average pressure coincide with the capillary pressure. However, when the fluids are in motion these quantities are dominated by viscous forces. In this case, only a definition based on the variation of the interfacial energy provides an accurate measure of the macroscopic capillary pressure and allows separating the viscous from the capillary pressure components.

Does Direct Democracy Matters for Political Parties : An Empirical Test in the Swiss Cantons

According to most political scientists and commentators, direct democracy seems to weaken political parties. Our empirical analysis in the 26 Swiss cantons shows that this thesis in its general form cannot be maintained. Political parties in cantons with extensive use of referendums and initiatives are not in all respects weaker than parties in cantons with little use of direct democratic means of participation. On the contrary, direct democracy goes together with more professional and formalized party organizations. Use of direct democracy is associated with more fragmented and volatile party systems, and with greater support for small parties, but causal interpretations of these relationships are difficult.

Direct Fourier Tomographic Reconstruction Image-To-Image Filter

We present an open-source ITK implementation of a directFourier method for tomographic reconstruction, applicableto parallel-beam x-ray images. Direct Fourierreconstruction makes use of the central-slice theorem tobuild a polar 2D Fourier space from the 1D transformedprojections of the scanned object, that is resampled intoa Cartesian grid. Inverse 2D Fourier transform eventuallyyields the reconstructed image. Additionally, we providea complex wrapper to the BSplineInterpolateImageFunctionto overcome ITKâeuro?s current lack for image interpolatorsdealing with complex data types. A sample application ispresented and extensively illustrated on the Shepp-Loganhead phantom. We show that appropriate input zeropaddingand 2D-DFT oversampling rates together with radial cubicb-spline interpolation improve 2D-DFT interpolationquality and are efficient remedies to reducereconstruction artifacts.

Les interventions de soutien direct auprès des aidants naturels réduisent leur détresse psychologique: revue Cochrane pour le praticien.

Cet article présente les résultats de la revue systématique: Candy B, Jones L, Drake R, Leurent B, King M. Interventions for supporting informal caregivers of patients in the terminal phase of a disease. Cochrane Database Syst Rev. 2011 Jun 15;(6):CD007617. PMID: 21678368. Contexte : Les aidants naturels sont des personnes bénévoles qui dispensent des soins physiques et, ou un soutien émotionnel à l'un(e) de leur proche ou ami(e). Ceci peut générer un stress intense tant physique que psychique. Des interventions visant principalement à augmenter la qualité de vie et à soutenir la vie affective des aidants naturels ont été développées. Cette revue systématique évalue l'effet de ces interventions sur la santé physique et psychique des aidants naturels de patients en phase terminale. [Auteurs]

Bone marrow dosimetry in rats using direct tissue counting after injection of radio-iodinated intact monoclonal antibodies or F(ab')2 fragments.

Normal rats were injected intravenously with 131I- and 125I-labeled intact murine and chimeric mouse-human monoclonal antibodies directed against carcinoembryonic antigen or with the corresponding F(ab')2 fragments. At different times after injection, individual animals were killed and radioactivity of blood and major organs, including bones and bone marrow, was determined. Ratios comparing radioactivity concentration in different tissues with that of bone marrow were calculated and found to remain stable during several effective half-lives of the antibodies. Mean bone marrow radioactivity was 35% (range, 29%-40%) of that of blood and 126% (range, 108%-147%) of that of liver after injection of intact Mabs or F(ab')2 fragments. In nude rats bearing human colon carcinoma xenografts producing carcinoembryonic antigen, relative bone marrow radioactivity was slightly lower than that in normal rats.

Influence of the menstrual cycle on the sweating response measured by direct calorimetry in women exposed to warm environmental conditions.

The whole body sweating response was measured at rest in eight women during the follicular (F) and the luteal (L) phases of the menstrual cycle. Subjects were exposed for 30-min to neutral (N) environmental conditions [ambient temperature (Ta) 28 degrees C] and then for 90-min to warm (W) environmental conditions (Ta, 35 degrees C) in a direct calorimeter. At the end of the N exposure, tympanic temperature (Tty) was 0.18 (SEM 0.06) degrees C higher in the L than in the F phase (P less than 0.05), whereas mean skin temperature (Tsk) was unchanged. During W exposure, the time to the onset of sweating as well as the concomitant increase in body heat content were similar in both phases. At the onset of sweating, the tympanic threshold temperature (Tty,thresh) was higher in the L phase [37.18 (SEM 0.08) degrees C] than in the F phase [36.95 (SEM 0.07) degrees C; P less than 0.01]. The magnitude of the shift in Tty,thresh [0.23 (SEM 0.07) degrees C] was similar to the L-F difference in Tty observed at the end of the N exposure. The mean skin threshold temperature was not statistically different between the two phases. The slope of the relationship between sweating rate and Tty was similar in F and L. It was concluded that the internal set point temperature of resting women exposed to warm environmental conditions shifted to a higher value during the L phase compared to the F phase of the menstrual cycle; and that the magnitude of the shift corresponded to the difference in internal temperature observed in neutral environmental conditions between the two phases.

Maintenance of ancestral sex chromosomes in Palearctic tree frogs: direct evidence from Hyla orientalis.

Contrasting with the situation found in birds and mammals, sex chromosomes are generally homomorphic in poikilothermic vertebrates. This homomorphy was recently shown to result from occasional X-Y recombinations (not from turnovers) in several European species of tree frogs (Hyla arborea, H. intermedia and H. molleri). Because of recombination, however, alleles at sex-linked loci were rarely diagnostic at the population level; support for sex linkage had to rely on multilocus associations, combined with occasional sex differences in allelic frequencies. Here, we use direct evidence, obtained from anatomical and histological analyses of offspring with known pedigrees, to show that the Eastern tree frog (H. orientalis) shares the same pair of sex chromosomes, with identical patterns of male heterogamety and complete absence of X-Y recombination in males. Conservation of an ancestral pair of sex chromosomes, regularly rejuvenated via occasional X-Y recombination, seems thus a widespread pattern among Hyla species. Sibship analyses also identified discrepancies between genotypic and phenotypic sex among offspring, associated with abnormal gonadal development, suggesting a role for sexually antagonistic genes on the sex chromosomes.

The (partisan) role of the press in direct democratic campaigns : Evidence from a Swiss vote on European integration

This article analyzes the role of the press in direct democratic campaigns. The paper argues the press has a dual role: On news pages, newspapers ought to inform citizens about the issue positions and frames of the pro and con camps in a balanced way. In editorials, newspapers act as political advocates that promote their own issue frames and try to shape public opinion through voting recommendations. Comparing the issue positions and frames in editorials and news reports in the run-up to the vote on the popular initiative "Yes to Europe" in Switzerland, this article shows that newspapers give similar visibility to the pro and con camps regardless of the papers' own editorial position. However, some newspapers favor issue frames that are in line with their editorial perspectives. In conclusion, newspapers are more similar in news report content than in editorial views.

Insertion of green fluorescent protein into nonstructural protein 5A allows direct visualization of functional hepatitis C virus replication complexes.

Hepatitis C virus (HCV) replicates its genome in a membrane-associated replication complex, composed of viral proteins, replicating RNA and altered cellular membranes. We describe here HCV replicons that allow the direct visualization of functional HCV replication complexes. Viable replicons selected from a library of Tn7-mediated random insertions in the coding sequence of nonstructural protein 5A (NS5A) allowed the identification of two sites near the NS5A C terminus that tolerated insertion of heterologous sequences. Replicons encoding green fluorescent protein (GFP) at these locations were only moderately impaired for HCV RNA replication. Expression of the NS5A-GFP fusion protein could be demonstrated by immunoblot, indicating that the GFP was retained during RNA replication and did not interfere with HCV polyprotein processing. More importantly, expression levels were robust enough to allow direct visualization of the fusion protein by fluorescence microscopy. NS5A-GFP appeared as brightly fluorescing dot-like structures in the cytoplasm. By confocal laser scanning microscopy, NS5A-GFP colocalized with other HCV nonstructural proteins and nascent viral RNA, indicating that the dot-like structures, identified as membranous webs by electron microscopy, represent functional HCV replication complexes. These findings reveal an unexpected flexibility of the C-terminal domain of NS5A and provide tools for studying the formation and turnover of HCV replication complexes in living cells.

Hepatitis B and C virus coinfection: a novel model system reveals the absence of direct viral interference.

Coinfection with hepatitis B virus (HBV) and hepatitis C virus (HCV) has been associated with severe liver disease and frequent progression to cirrhosis and hepatocellular carcinoma. Clinical evidence suggests reciprocal replicative suppression of the two viruses, or viral interference. However, interactions between HBV and HCV have been difficult to study due to the lack of appropriate model systems. We have established a novel model system to investigate interactions between HBV and HCV. Stable Huh-7 cell lines inducibly replicating HBV were transfected with selectable HCV replicons or infected with cell culture-derived HCV. In this system, both viruses were found to replicate in the same cell without overt interference. Specific inhibition of one virus did not affect the replication and gene expression of the other. Furthermore, cells harboring replicating HBV could be infected with cell culture-derived HCV, arguing against superinfection exclusion. Finally, cells harboring replicating HBV supported efficient production of infectious HCV. Conclusion: HBV and HCV can replicate in the same cell without evidence for direct interference in vitro. Therefore, the viral interference observed in coinfected patients is probably due to indirect mechanisms mediated by innate and/or adaptive host immune responses. These findings provide new insights into the pathogenesis of HBV-HCV coinfection and may contribute to its clinical management in the future.

Mario Ruspoli et le "cinéma direct"

La production Argos Films édite chez Montparnasse le premier coffret DVD des principaux films du cinéaste. Profitant de cette accessibilité nouvelle, Décadrages a choisi de consacrer son 18e numéro à l'apport fondamental de Mario Ruspoli dans l'émergence, vers 1960, du cinéma documentaire en caméra légère, afin d'éclairer le contexte technique, discursif, théorique et artistique de cette production. Ce volume espère ainsi pallier cette méconnaissance de Mario Ruspoli en proposant, à travers cinq articles, la première publication universitaire sur ce cinéaste franco-italien.