110 research outputs found

    Infection of neonatal mice with the murine norovirus strain WU23 is a robust model to study norovirus pathogenesis

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    Noroviruses are the leading cause of severe childhood diarrhea and foodborne disease worldwide. While they are a major cause of disease in all age groups, infections in the very young can be quite severe, with annual estimates of 50,000-200,000 fatalities in children under 5 years old. In spite of the remarkable disease burden associated with norovirus infections, very little is known about the pathogenic mechanisms underlying norovirus diarrhea, principally because of the lack of tractable small animal models. The development of the murine norovirus (MNV) model nearly two decades ago has facilitated progress in understanding host-norovirus interactions and norovirus strain variability. However, MNV strains tested thus far either do not cause intestinal disease or were isolated from extraintestinal tissue, raising concerns about translatability of research findings to human norovirus disease. Consequently, the field lacks a strong model of norovirus gastroenteritis. Here we provide a comprehensive characterization of a new small animal model system for the norovirus field that overcomes prior weaknesses. Specifically, we demonstrate that the WU23 MNV strain isolated from a mouse naturally presenting with diarrhea causes a transient reduction in weight gain and acute self-resolving diarrhea in neonatal mice of several inbred mouse lines. Moreover, our findings reveal that norovirus-induced diarrhea is associated with infection of subepithelial cells in the small intestine and systemic spread. Finally, type I interferons (IFNs) are critical to protect hosts from norovirus-induced intestinal disease whereas type III IFNs exacerbate diarrhea. This latter finding is consistent with other emerging data implicating type III IFNs in the exacerbation of some viral diseases. This new model system should enable a detailed investigation of norovirus disease mechanisms

    Design criteria of the bolometer diagnostic for steady-state operation of the W7-X stellarator

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    A bolometric diagnostic system with features necessary for steady-state operation in the superconducting stellarator W7-X was designed. During a pulse length of 1800 s with an ECRH (electron cyclotron resonance heating) power of 10 MW, the components suffer not only from a large thermal load but also from stray radiation of the nonabsorbed isotropic microwaves. This paper gives an overview of the technical problems encountered during the design work and the solutions to individual problems to meet the special requirements in W7-X, e.g., component thermal protection, detector offset thermal drift suppression, as well as a microwave shielding technique. © 2010 American Institute of Physic

    European guidelines on structure and qualification of general thoracic surgery

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    OBJECTIVE To update the recommendations for the structural characteristics of general thoracic surgery (GTS) in Europe in order to provide a document that can be used as a guide for harmonizing the general thoracic surgical practice in Europe. METHODS A task force was created to set the structural, procedural and qualification characteristics of a European GTS unit. These criteria were endorsed by the Executive Committee of the European Society of Thoracic Surgeons and by the Thoracic Domain of the European Association for Cardio-Thoracic Surgery and were validated by the European Board of Thoracic Surgery at European Union of Medical Specialists. RESULTS Criteria regarding definition and scope of GTS, structure and qualification of GTS unit, training and education and recommendations for subjects of particular interest (lung transplant, oesophageal surgery, minimally invasive thoracic surgery, quality surveillance) were developed. CONCLUSIONS This document will hopefully represent the first step of a process of revision of the modern thoracic surgeons' curricula, which need to be qualitatively rethought in the setting of the qualification process. The structural criteria highlighted in the present document are meant to help and tackle the challenge of cultural and language barriers as well as of widely varying national training programme

    Characterization and Whole Genome Analysis of Human Papillomavirus Type 16 E1-1374^63nt Variants

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    Background. The variation of the most common Human papillomavirus (HPV) type found in cervical cancer, the HPV16, has been extensively investigated in almost all viral genes. The E1 gene variation, however, has been rarely studied. The main objective of the present investigation was to analyze the variability of the E6 and E1 genes, focusing on the recently identified E1-1374^63nt variant. Methodology/Principal Findings. Variation within the E6 of 786 HPV16 positive cervical samples was analyzed using high-resolution melting, while the E1-1374^63nt duplication was assayed by PCR. Both techniques were supplemented with sequencing. The E1-1374^63nt duplication was linked with the E-G350 and the E-C109/G350 variants. In comparison to the referent HPV16, the E1-1374^63nt E-G350 variant was significantly associated with lower grade cervical lesions (p=0.029), while the E1-1374^63nt E-C109/G350 variant was equally distributed between high and low grade lesions. The E1-1374^63nt variants were phylogenetically closest to E-G350 variant lineage (A2 sub-lineage based on full genome classification). The major differences between E1-1374^63nt variants were within the LCR and the E6 region. On the other hand, changes within the E1 region were the major differences from the A2 sub-lineage, which has been historically but inconclusively associated with high grade cervical disease. Thus, the shared variations cannot explain the particular association of the E1-1374^63nt variant with lower grade cervical lesions. Conclusions/Significance. The E1 region has been thus far considered to be well conserved among all HPVs and therefore uninteresting for variability studies. However, this study shows that the variations within the E1 region could possibly affect cervical disease, since the E1-1374^63nt E-G350 variant is significantly associated with lower grade cervical lesions, in comparison to the A1 and A2 sub-lineage variants. Furthermore, it appears that the silent variation 109T>C of the E-C109/G350 variant might have a significant role in the viral life cycle and warrants further study

    Influences de la sylviculture sur le risque de dégâts biotiques et abiotiques dans les peuplements forestiers

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    Impacts of soil conditions and light availability on natural regeneration of Norway spruce Picea abies (L.) H. Karst. in low-elevation mountain forests

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    & Key message Natural regeneration of P. abies (L.) H. Karst. may reach high densities in lower mountain elevations. The highest densities were found in sites with moderate light availability, with low pH, and not near the riverbank. However, age-height classes differed in the predicted magnitude of response, but were consistent in response directions. Mosses and understory species typical of coniferous forests were positively correlated with regeneration density. & Context Norway spruce Picea abies (L.) H. Karst. in Central Europe is at risk under climate change scenarios, particularly in mountain regions. Little is known about the impact of environmental factors on the natural regeneration of P. abies in lowelevation mountain forests. & Aims We aimed to assess impacts of distance from the riverbank, soil pH, and light availability on natural P. abies regeneration. We hypothesized that (1) natural P. abiesregeneration would depend on light availability and soil pH and (2) there are understory plant species which may indicate the microsites suitable for natural regeneration of P. abies. & Methods The study was conducted in the Stołowe Mountains National Park (SW Poland, 600–800 m a.s.l.). We established 160 study plots (25 m2 ) for natural regeneration, light availability, soil pH, and understory vegetation assessment

    The effect of synthetic pheromones on the infestation of trap logs by Pityogenes chalcographus (L.) (Col.: Scolytidae)

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    The classic trap logs are attractive for Pityogenes chalcographus. The infestation density and the length of infested part of stem can be increased by the use of synthetic pheromones of this species. The use of trap logs is generally recommended, but their effectiveness can be enhanced by the use of synthetic pheromones
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