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.

Advanced Kernel Methods For Remote Sensing Image Classification

Résumé Suite aux recentes avancées technologiques, les archives d'images digitales ont connu une croissance qualitative et quantitative sans précédent. Malgré les énormes possibilités qu'elles offrent, ces avancées posent de nouvelles questions quant au traitement des masses de données saisies. Cette question est à la base de cette Thèse: les problèmes de traitement d'information digitale à très haute résolution spatiale et/ou spectrale y sont considérés en recourant à des approches d'apprentissage statistique, les méthodes à noyau. Cette Thèse étudie des problèmes de classification d'images, c'est à dire de catégorisation de pixels en un nombre réduit de classes refletant les propriétés spectrales et contextuelles des objets qu'elles représentent. L'accent est mis sur l'efficience des algorithmes, ainsi que sur leur simplicité, de manière à augmenter leur potentiel d'implementation pour les utilisateurs. De plus, le défi de cette Thèse est de rester proche des problèmes concrets des utilisateurs d'images satellite sans pour autant perdre de vue l'intéret des méthodes proposées pour le milieu du machine learning dont elles sont issues. En ce sens, ce travail joue la carte de la transdisciplinarité en maintenant un lien fort entre les deux sciences dans tous les développements proposés. Quatre modèles sont proposés: le premier répond au problème de la haute dimensionalité et de la redondance des données par un modèle optimisant les performances en classification en s'adaptant aux particularités de l'image. Ceci est rendu possible par un système de ranking des variables (les bandes) qui est optimisé en même temps que le modèle de base: ce faisant, seules les variables importantes pour résoudre le problème sont utilisées par le classifieur. Le manque d'information étiquétée et l'incertitude quant à sa pertinence pour le problème sont à la source des deux modèles suivants, basés respectivement sur l'apprentissage actif et les méthodes semi-supervisées: le premier permet d'améliorer la qualité d'un ensemble d'entraînement par interaction directe entre l'utilisateur et la machine, alors que le deuxième utilise les pixels non étiquetés pour améliorer la description des données disponibles et la robustesse du modèle. Enfin, le dernier modèle proposé considère la question plus théorique de la structure entre les outputs: l'intègration de cette source d'information, jusqu'à présent jamais considérée en télédétection, ouvre des nouveaux défis de recherche. Advanced kernel methods for remote sensing image classification Devis Tuia Institut de Géomatique et d'Analyse du Risque September 2009 Abstract The technical developments in recent years have brought the quantity and quality of digital information to an unprecedented level, as enormous archives of satellite images are available to the users. However, even if these advances open more and more possibilities in the use of digital imagery, they also rise several problems of storage and treatment. The latter is considered in this Thesis: the processing of very high spatial and spectral resolution images is treated with approaches based on data-driven algorithms relying on kernel methods. In particular, the problem of image classification, i.e. the categorization of the image's pixels into a reduced number of classes reflecting spectral and contextual properties, is studied through the different models presented. The accent is put on algorithmic efficiency and the simplicity of the approaches proposed, to avoid too complex models that would not be used by users. The major challenge of the Thesis is to remain close to concrete remote sensing problems, without losing the methodological interest from the machine learning viewpoint: in this sense, this work aims at building a bridge between the machine learning and remote sensing communities and all the models proposed have been developed keeping in mind the need for such a synergy. Four models are proposed: first, an adaptive model learning the relevant image features has been proposed to solve the problem of high dimensionality and collinearity of the image features. This model provides automatically an accurate classifier and a ranking of the relevance of the single features. The scarcity and unreliability of labeled. information were the common root of the second and third models proposed: when confronted to such problems, the user can either construct the labeled set iteratively by direct interaction with the machine or use the unlabeled data to increase robustness and quality of the description of data. Both solutions have been explored resulting into two methodological contributions, based respectively on active learning and semisupervised learning. Finally, the more theoretical issue of structured outputs has been considered in the last model, which, by integrating outputs similarity into a model, opens new challenges and opportunities for remote sensing image processing.

Spatial analysis of erythrocyte membrane fluctuations by digital holographic microscopy.

Red blood cell (RBC) membrane fluctuations provide important insights into cell states. We present a spatial analysis of red blood cell membrane fluctuations by using digital holographic microscopy (DHM). This interferometric and dye-free technique, possessing nanometric axial and microsecond temporal sensitivities enables to measure cell membrane fluctuations (CMF) on the whole cell surface. DHM acquisition is combined with a model which allows extracting the membrane fluctuation amplitude, while taking into account cell membrane topology. Uneven distribution of CMF amplitudes over the RBC surface is observed, showing maximal values in a ring corresponding to the highest points on the RBC torus as well as in some scattered areas in the inner region of the RBC. CMF amplitudes of 35.9+/-8.9 nm and 4.7+/-0.5 nm (averaged over the cell surface) were determined for normal and ethanol-fixed RBCs, respectively.

SELEÇÃO DE DENSIDADE DE AMOSTRAGEM COM BASE EM DADOS DE ÁREAS JÁ MAPEADAS PARA TREINAMENTO DE MODELOS DE ÁRVORE DE DECISÃO NO MAPEAMENTO DIGITAL DE SOLOS

Para estudar técnicas de amostragem, úteis ao mapeamento digital de solos (MDS), objetivou-se avaliar o efeito da variação da densidade de pontos amostrais com base em dados de áreas já mapeadas por métodos tradicionais na acurácia dos modelos de árvores de decisão (AD) para a geração de mapas de solos por MDS. Em duas bacias hidrográficas no noroeste do Rio Grande do Sul, usou-se, como referência, antigos mapas convencionais de solos na escala 1:50.000. A partir do modelo digital de elevação do terreno e da rede hidrográfica, foram gerados mapas das variáveis preditoras: elevação, declividade, curvatura, comprimento de fluxo, acúmulo de fluxo, índice de umidade topográfica e distância euclideana de rios. A escolha dos locais dos pontos amostrais foi aleatória e testaram-se densidades amostrais que variaram de 0,1 a 4 pontos/ha. O treinamento dos modelos foi realizado no software Weka, gerando-se modelos preditores usando diferentes tamanhos do nó final da AD para obter AD com tamanhos distintos. Quando não se controlou o tamanho das AD, o aumento da densidade de amostragem resultou no aumento da concordância com os mapas básicos de referências e no aumento do número de unidades de mapeamento preditas. Nas AD com tamanho controlado, o aumento da densidade de amostragem não influenciou a concordância com os mapas de referência e interferiu muito pouco no número de unidades de mapeamento preditas.

Multiple Geotechnological Tools Applied to Digital Mapping of Tropical Soils

ABSTRACT In recent years, geotechnologies as remote and proximal sensing and attributes derived from digital terrain elevation models indicated to be very useful for the description of soil variability. However, these information sources are rarely used together. Therefore, a methodology for assessing and specialize soil classes using the information obtained from remote/proximal sensing, GIS and technical knowledge has been applied and evaluated. Two areas of study, in the State of São Paulo, Brazil, totaling approximately 28.000 ha were used for this work. First, in an area (area 1), conventional pedological mapping was done and from the soil classes found patterns were obtained with the following information: a) spectral information (forms of features and absorption intensity of spectral curves with 350 wavelengths -2,500 nm) of soil samples collected at specific points in the area (according to each soil type); b) obtaining equations for determining chemical and physical properties of the soil from the relationship between the results obtained in the laboratory by the conventional method, the levels of chemical and physical attributes with the spectral data; c) supervised classification of Landsat TM 5 images, in order to detect changes in the size of the soil particles (soil texture); d) relationship between classes relief soils and attributes. Subsequently, the obtained patterns were applied in area 2 obtain pedological classification of soils, but in GIS (ArcGIS). Finally, we developed a conventional pedological mapping in area 2 to which was compared with a digital map, ie the one obtained only with pre certain standards. The proposed methodology had a 79 % accuracy in the first categorical level of Soil Classification System, 60 % accuracy in the second category level and became less useful in the categorical level 3 (37 % accuracy).

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.

A simple blood-culture bacterial pellet preparation for faster accurate direct bacterial identification and antibiotic susceptibility testing with the VITEK 2 system.

An ammonium chloride procedure was used to prepare a bacterial pellet from positive blood cultures, which was used for direct inoculation of VITEK 2 cards. Correct identification reached 99% for Enterobacteriaceae and 74% for staphylococci. For antibiotic susceptibility testing, very major and major errors were 0.1 and 0.3% for Enterobacteriaceae, and 0.7 and 0.1% for staphylococci, respectively. Thus, bacterial pellets prepared with ammonium chloride allow direct inoculation of VITEK cards with excellent accuracy for Enterobacteriaceae and a lower accuracy for staphylococci.

Direct Care Worker Compensation Advisory Committee Review and Recommendation Report, December 11, 2008

The 2008 general assembly acknowledged in House File 2539, Section 70 that is recognizes direct care workers play a vital role and make a valuable contribution to Iowa's Health Care Reform efforts in providing care to Iowans with a variety of needs in both institutional and home and community based settings. the legislation identified that recruiting and retaining highly competent direct care workers is a challenge across all healthcare employment settings.

Report to the Governor and General Assembly on Voluntary Employer-Sponsored Health Care Coverage Demonstration Project-Non-licensed Direct Care Workers, December 2008

Iowa faces a growing crisis in providing an adequate number of direct care workers for its again population. Direct care workers caring for the aging and disabled population are among those in our work force with the lowest wages and lack of access to health insurance. A survey of direct care workers conducted by the Iowa Caregivers Association in June of 2066 indicated that benefits ranked second only to wages in the reasons for job-hoping. A study of the direct care workforce in Vermont healthy insurance, ranked second only to wages, as important to attracting and keeping direct care workers.

A two-level analysis of the determinants of direct democratic choices in European, immigration and foreign policy in Switzerland

This article employs a unique data set - covering 25 popular votes on foreign, European and immigration/asylum policy held between 1992 and 2006 in Switzerland - in order to examine the conditional impact of context upon utilitarian, cultural, political and cognitive determinants of individual attitudes toward international openness. Our results reveal clear patterns of cross-level interactions between individual determinants and the project-related context of the vote. Thus, although party cues and political competence have a strong impact on individuals' support for international openness, this impact is substantially mediated by the type of coalition that is operating within the party elite. Similarly, subjective utilitarian and cultural considerations influence the voters' decision in interaction with the content of the proposal submitted to the voters as well as with the framing of the voting campaign.

Application of direct-infusion ESI-MS/MS for toxicological screening.

BACKGROUND: Direct-infusion ESI-MS/MS is a powerful approach for the identification of substances in complex mixtures. The aim of this work was to investigate its applicability to the toxicological screening of blood samples. A simple protein precipitation was used, followed by a 15 min infusion of the extract in the mass spectrometer. RESULTS: The application of the procedure to commercial quality controls and authentic post-mortem blood samples demonstrated that the direct-infusion ESI-MS/MS approach enables the simultaneous identification of substances that require different chromatographic conditions. However, poor sensitivity was observed for benzodiazepine, amphetamines and opiate compounds. CONCLUSION: Considering the facile implementation and positive performance of direct-infusion ESI-MS/MS, this approach may to be a valuable complementary technique for systematic toxicological analysis procedures.

Digital holographic microscopy: a noninvasive contrast imaging technique allowing quantitative visualization of living cells with subwavelength axial accuracy.

We have developed a digital holographic microscope (DHM), in a transmission mode, especially dedicated to the quantitative visualization of phase objects such as living cells. The method is based on an original numerical algorithm presented in detail elsewhere [Cuche et al., Appl. Opt. 38, 6994 (1999)]. DHM images of living cells in culture are shown for what is to our knowledge the first time. They represent the distribution of the optical path length over the cell, which has been measured with subwavelength accuracy. These DHM images are compared with those obtained by use of the widely used phase contrast and Nomarski differential interference contrast techniques.

Precision of tibial tunnel placement under arthroscopic control alone in posterior cruciate ligament reconstruction: A radiological study

Introduction: Accurate and reproducible tibial tunnel placement minimizing the risk of neurovascular damage is a crucial condition for successful arthroscopic reconstruction of the posterior cruciate ligament (PCL). This step is commonly performed under fluoroscopic control. Hypothesis: Performing the tibial tunnel under exclusive arthroscopic control allows accurate and reliable tunnel placement according to recommendations in the literature. Materials and Methods: Between February 2007 and December 2009, 108 arthroscopic single bundle PCL reconstructions in tibial tunnel technique were performed. The routine postoperative radiographs were screened according to previously defined quality criterions. After critical analysis, the radiographs of 48 patients (48 knees) were enrolled in the study. 10 patients had simultaneous ACL reconstruction and 7 had PCL revision surgery. The tibial tunnel was placed under direct arthroscopic control through a posteromedial portal using a standard tibial aming device. Key anatomical landmarks were the exposed tibial insertion of the PCL and the posterior horn of the medial meniscus. First, the centre of the posterior tibial tunnel outlet on the a-p view was determined by digital analysis of the postoperative radiographes. Its distance to the medial tibial spine was measured parallel to the tibia plateau. The mediolateral position was expressed by the ratio between the distance of the tunnel outlet to the medial border and the total width of the tibial plateau. On the lateral view the vertical tunnel position was measured perpendicularly to a tangent of the medial tibial plateau. All measurement were repeated at least twice and carried out by two examiners. Results: The mean mediolateral tunnel position was 49.3 ± 4.6% (ratio), 6.7 ± 3.6 mm lateral to the medial tibial spine. On the lateral view the tunnel centre was 10.1 ± 4.5 mm distal to the bony surface of the medial tibial plateau. Neurovascular damage was observed in none of our patients. Conclusion: The results of this radiological study confirm that exclusive arthroscopic control for tibial tunnel placement in PCL reconstruction yields reproducible and accurate results according to the literature. Our technique avoids radiation, facilitates the operation room setting and enables the surgeon to visualize the anatomic key landmarks for tibial tunnel placement.