The Australian Rotavirus Surveillance Program together with 15 collaborating laboratories Australia-wide conducts a laboratory based rotavirus surveillance program. This report describes the ...genotypes of rotavirus strains responsible for the hospitalisation of children with acute gastroenteritis during the period 1 July 2009 to 30 June 2010, the 3rd year of surveillance following introduction of rotavirus vaccines into the National Immunisation Program. Seven hundred and seventy-eight faecal samples were referred to the centre for G and P genotype analysis using hemi-nested multiplex reverse transcription-polymerase chain reaction. Of the 422 confirmed as rotavirus positive, genotype G1P8 was the dominant type nationally, representing 49.3%, followed by genotype G2P4 (21.1%). Genotypes G3P8, G4P8 and G9P8 each represented less than 3% of circulating strains nationally. The dominance of G1P8 was in part associated with a large outbreak of severe gastroenteritis in the Northern Territory in 2010. The identification of uncommon rotavirus genotype combinations has increased since vaccine introduction, with G1P4, G2P8 and G9P4 identified during this survey. Single strains of G1P6 and G4P6 were identified during this study period. This survey continues to highlight the fluctuations in rotavirus genotypes, and results from this survey suggest there is limited genotype selection based on vaccine usage. However, the large G1P8 outbreak of gastroenteritis in the Northern Territory may have resulted from vaccine pressure on wild-type strains.
Abstract Rotavirus is the most common cause of acute severe dehydrating diarrhoea in young children worldwide. We describe the burden of rotavirus disease and the rotavirus types causing it in the ...largest city in Fiji. During 2006 and 2007, 592 children under 5 years of age were admitted to hospital in Suva, Fiji with acute diarrhoea. Of the 454 children for whom a stool specimen was tested, 39% were positive for rotavirus and the predominant strain found was the serotype G3P8. There is a significant burden of disease due to rotavirus in Fiji and the introduction of rotavirus vaccines into the national immunization schedule may drastically reduce inpatient diarrhoeal disease.
The Australian Rotavirus Surveillance Program together with collaborating laboratories Australia-wide, conducts a laboratory based rotavirus surveillance program. This report describes the genotypes ...of rotavirus strains responsible for the hospitalisation of children with acute gastroenteritis during the period 1 July 2008 to 30 June 2009, the second year of surveillance following introduction of rotavirus vaccine into the National Immunisation Program. Five hundred and ninety-two faecal samples from across Australia were examined for G and P genotype using hemi-nested multiplex reverse transcription-polymerase chain reaction assays. Of the 445 confirmed as rotavirus positive, genotype G2P4 was the dominant type nationally, representing 50.3%, followed by genotype G1P8 (22.5%). Genotypes G3P8, G4P8 and G9P8 each represented less than 5% of circulating strains nationally. Uncommon rotavirus genotype combinations, including G1P4 (n = 6), G4P4 (n = 2) and single strains of G1P6 and G3P6 were identified during this study period. The national dominance of G2P4 was associated with a large outbreak of severe gastroenteritis in Alice Springs in early 2009. This is the first report to describe G2P4 as the dominant genotype nationally. Whether vaccine pressure has resulted in emergence of this genotype is not yet known.
The small GTPase RhoA modulates the adhesive nature of many cell types; however, despite high levels of expression in platelets, there is currently limited evidence for an important role for this ...small GTPase in regulating platelet adhesion processes. In this study, we have examined the role of RhoA in regulating the adhesive function of the major platelet integrin, αIIbβ3. Our studies demonstrate that activation of RhoA occurs as a general feature of platelet activation in response to soluble agonists (thrombin, ADP, U46619, collagen), immobilized matrices (von Willebrand factor (vWf), fibrinogen) and high shear stress. Blocking the ligand binding function of integrin αIIbβ3, by pretreating platelets with c7E3 Fab, demonstrated the existence of integrin αIIbβ3-dependent and -independent mechanisms regulating RhoA activation. Inhibition of RhoA (C3 exoenzyme) or its downstream effector Rho kinase (Y27632) had no effect on integrin αIIbβ3 activation induced by soluble agonists or adhesive substrates, however, both inhibitors reduced shear-dependent platelet adhesion on immobilized vWf and shear-induced platelet aggregation in suspension. Detailed analysis of the sequential adhesive steps required for stable platelet adhesion on a vWf matrix under shear conditions revealed that RhoA did not regulate platelet tethering to vWf or the initial formation of integrin αIIbβ3 adhesion contacts but played a major role in sustaining stable platelet-matrix interactions. These studies define a critical role for RhoA in regulating the stability of integrin αIIbβ3adhesion contacts under conditions of high shear stress.
Rotaviruses are the single most important causes of severe acute diarrhoea in children worldwide. Despite success in developing vaccines, there is still a lack of knowledge about many components of ...the immune response, particularly those to non-structural proteins. This study established radioimmunoprecipitation (RIP) assays using labeled G1P8, G2P4, and G4P6 human rotaviruses to examine the spectrum and duration of rotavirus antibodies in sera collected sequentially for 18-36 months from 27 children after hospitalization for primary rotavirus gastroenteritis. Five children experienced rotavirus re-infections. Primary responses detected to non-structural protein NSP2 declined to baseline after 100-150 days. Responses were heterotypic between NSP2 of G1P8 and G4P8 rotaviruses. Re-infections after 465-786 days boosted antibody levels to NSP2of both serotypes, together with the appearance of anti-NSP2 to G2P4, even though there was no evidence of infection with this serotype. We developed an enzyme-immunoassay to measure sequential levels of anti-NSP2 IgG and IgA, using recombinant (heterotypic) NSP2 derived from SA11 (G3P2). Anti-NSP2 IgG and IgA were detected in sera from 23/23 (100%) and 18/24 (75%) of children after primary infection, declined to baseline after 100-150 days, were boosted after rotavirus re-infections, and again declined to baseline 150 days later. Anti-NSP2 IgA was also detected after primary infection, in duodenal juice from 14/16 (87%), and faecal extract from 11/19 (57%) of children. Sequential estimation of anti-NSP2 EIA levels in sera could be a sensitive index of rotavirus infection and re-infection. The potential of anti-NSP2 to limit viral replication after re-infection deserves further study. J. Med. Virol. 80:1090-1098, 2008.
La vapeur d'eau varie largement dans l'atmosphère avec des concentrations allant de la saturation dans les tropiques à des zones presque sèches au-dessus des zones continentales élevées. Une bonne ...connaissance du contenu en vapeur d'eau dans l'air est nécessaire pour la prévision des changements de phases, notamment les précipitations. La mesure de la variabilité de la vapeur d'eau est une lacune des systèmes d'observation. Par ailleurs, il est apparu que le positionnement précis des antennes GPS était affecté par la variation de l'indice de réfraction dans la troposphère, ce qui rend particulièrement difficile l'estimation de la composante verticale. Cette variation est directement liée à la distribution des variables pression, température et humidité sur les trajets satellite-récepteur. On s'intéresse ici à l'étude des précipitations intenses et notamment aux épisodes Cévenols. Ce travail de thèse consiste à vérifier la validité de la mesure GPS pour la quantification de la vapeur d'eau en la comparant avec des mesures issues de radiosondage et des sorties de modèle météorologique. On cherche à analyser si la quantification de vapeur d'eau par GPS permet de caractériser les forts événements précipitants (cumuls supérieurs à 150 mm) à l'aide d'observations conjointes sur les flux de surface. On étudie ensuite l'impact de l'assimilation de données GPS issues d'un réseau GPS dense sur la prévision des cumuls de pluies dans le modèle à hauterésolution (2.5 km) AROME de Météo France. Finalement on évalue la qualité et l'apport de la mesure de vapeur d'eau par GPS en mer dans le cadre d'une campagne de mesure VAPIMED).
Both the Arctic and Space are important policy topics for the EU, with recently defined strategies and programs. The European Commission's Joint Research Centre has recently completed a study upon ...the request of the Directorate Defense Industry and Space (DEFIS) aiming at identifying the synergies across the four domains of the EU Space Programme. This study surveys the EU's space-based capabilities, related to Earth observation (EO), navigation, communication and space monitoring, and highlights their current and potential future relevance for users in the Arctic. The user-needs across the four main domains are provided, covering the maritime sector, disaster risk management, monitoring essential climate variables and regulatory compliance, search and rescue services, communications and satellite service disruption. Users cover both science and operational users but also indigenous and local community users. Challenges are then discussed related to the different domains of applications. Then, the study provides a large inventory of the current and future (i.e. next decade) European capacities in the Arctic. Finally, it discusses promising synergistic uses of space assets and applications, and presents a brief societal impact assessment. These synergies are expected to be key enablers of new services that will have a high societal impact in the region, which could be developed in a more cost-efficient and rapid manner. Similarly, synergies will also help exploiting operational services that are already deployed in the Arctic. The study is based on discussions with various international experts from Academy to Industry from several areas, and on an extensive literature review covering high-quality sources. The study aims at reinforcing the efficiency of existing and future capabilities for the Arctic users and to improve the connectivity.
Both the Arctic and Space are important policy topics for the EU, with recently defined strategies and programs. This report surveys the EU's space-based capabilities, related to Earth observation, ...navigation, communication and space monitoring, and assesses their current and potential future relevance for users in the Arctic. It discusses promising synergistic uses of space assets and applications, and presents a brief societal impact assessment.
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