The gut mucosa is the principal site where Crohn's disease CD inflammation occurs. Limited information is available about the gut mucosal microbiome during CD relapse and remission. The aim of our ...study was to characterize specific changes in the gut microbiome during relapse and remission in a large single-centre paediatric CD cohort.
We analysed the microbiome of 345 biopsies from 204 patients, including 88 CD first diagnosis CDFD patients, 38 relapse CDRL patients, 12 remission CDRM patients, and 66 controls. Species identification was conducted using oligotyping in combination with ARB/SILVA taxonomic annotation.
We observed 45 bacteria to differ between CDFD samples and controls with statistical significance, with Fusobacterium being the most implicated species in CDFD patients. We also identified gender-specific differences in CD. Five species showed a strong association with CDRL patients and 10 species with CDRM patients. Three taxa showed a positive co-occurrence across the two groups. Hespellia porcina closest taxonomic neighbour to Clostridium oroticum was the most strongly associated with CDRL samples. Interestingly, Fusobacterium was not part of the CDRL-associated taxa group. Faecalibacterium prausnitzii was equally present in CDFD and control samples.
This is the first study that has investigated the gut mucosal microbiome in a paediatric CD cohort with longitudinal sampling. Importantly, the microbiome of patients in CDRM did not return to a healthy control state. Neither did the microbiome of patients with CDRL return to the profile seen at CDFD.
Impact of GPS (Global Positioning System) data assimilation is assessed here using a high-resolution numerical weather prediction system at 2.5 km horizontal resolution. The Zenithal Tropospheric ...Delay (ZTD) GPS data from mesoscale networks are assimilated with the 3DVAR AROME data assimilation scheme. Data from more than 280 stations over the model domain have been assimilated during 15-day long assimilation cycles prior each of the two studied events. The results of these assimilation cycles show that the assimilation of GPS ZTD with the AROME system performs well in producing analyses closer to the ZTD observations in average. Then the impacts of assimilating GPS data on the precipitation forecast have been evaluated. For the first case, only the AROME runs starting a few hours prior the triggering of the convective system are able to simulate the convective precipitation. The assimilation of GPS ZTD observations improves the simulation of the spatial extent of the precipitation, but slightly underestimates the heaviest precipitation in that case compared with the experiment without GPS. The accuracy of the precipitation forecast for the second case is much better. The analyses from the control assimilation cycle provide already a good description of the atmosphere state that cannot be further improved by the assimilation of GPS observations. Only for the latest day (22 November 2007), significant differences have been found between the two parallel cycles. In that case, the assimilation of GPS ZTD allows to improve the first 6 to 12 h of the precipitation forecast.
The validation of remote sensing environmental estimates requires knowledge of their spatial extent and resolution. Here, we consider coherent radio reflections routinely observed in ground-based ...global positioning system (GPS) reflectometry. Their footprint is often conceptualized in terms of the specular point (SP) and the first Fresnel zone (FFZ). Such infinitesimal point and finite zone can be generalized into a spatially continuous sensitivity kernel (SK). The SK represents a diffraction pattern, as the importance of each surface portion depends on its scattered field contribution in power and phase. We measured the SK of a GPS radio reflection under bipath reception conditions. The SK exhibited oscillations along the plane of incidence. The envelope of oscillations peaked near the SP and persisted in its decay well beyond the FFZ. Within the FFZ, sensitivity was skewed toward the antenna. This experiment suggests the feasibility of overcoming the diffraction limit and resolving features smaller than the FFZ with the exploitation of GPS diffraction patterns.
Abstract This study documents rotavirus strains causing severe disease in Australian children during the pre-vaccine era. During the period 1997–2007, rotavirus strains from national multi-centre ...hospital-based surveillance in Australia were analysed for G and P types. G1P8 was the dominant genotype identified during the 11-year study, with intermittent peaks associated with genotypes G2P4, G3P8 and G9P8. The results provide baseline information of the G and P genotypes causing disease in Australian children, and highlight the unpredictable changes in genotype incidence that can occur on both a local and national level. To be optimally effective, rotavirus vaccines must prevent disease caused by all common rotavirus genotypes.
Estimation of tropospheric gradients in GNSS data processing is a well-known technique to improve positioning (e.g. Bar-Sever et al., 1998; Chen and Herring, 1997). More recently, several authors ...also focused on the estimation of such parameters for meteorological studies and demonstrated their potential benefits (e.g. Champollion et al., 2004). Today, they are routinely estimated by several global and regional GNSS analysis centres but they are still not yet used for operational meteorology.
This paper discusses the physical meaning of tropospheric gradients estimated from GPS observations recorded in 2011 by 13 permanent stations located in Corsica Island (a French Island in the western part of Italy). Corsica Island is a particularly interesting location for such study as it presents a significant environmental contrast between the continent and the sea, as well as a steep topography.
Therefore, we estimated Zenith Total Delay (ZTD) and tropospheric gradients using two software: GAMIT/GLOBK (GAMIT version 10.5) and GIPSY-OASIS II version 6.1. Our results are then compared to radiosonde observations and to the IGS final troposphere products. For all stations we found a good agreement between the ZWD estimated by the two software (the mean of the ZWD differences is 1mm with a standard deviation of 6mm) but the tropospheric gradients are in less good agreement (the mean of the gradient differences is 0.1mm with a standard deviation of 0.7mm), despite the differences in the processing strategy (double-differences for GAMIT/GLOBK versus zero-difference for GIPSY-OASIS).
We also observe that gradient amplitudes are correlated with the seasonal behaviour of the humidity. Like ZWD estimates, they are larger in summer than in winter. Their directions are stable over the time but not correlated with the IWV anomaly observed by ERA-Interim. Tropospheric gradients observed at many sites always point to inland throughout the year. These preferred directions are almost opposite to the largest slope of the local topography as derived from the world Digital Elevation Model ASTER GDEM v2. These first results give a physical meaning to gradients but the origin of such directions need further investigations.
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 1 July 2010 to 30 June 2011. This report represents the fourth year of surveillance following introduction of rotavirus vaccines into the National Immunisation Program. One thousand one hundred and twenty-seven faecal samples were referred to the centre for G and P genotype analysis using hemi-nested multiplex reverse transcription-polymerase chain reaction. Eight hundred and sixteen samples were confirmed as rotavirus positive. Of these, 551 were collected from children under 5 years of age, while 265 were from older children and adults. Genotype analysis revealed that a change in the dominant type occurred in this reporting period, such that genotype G2P4 was the dominant type nationally, representing 51% of samples, followed by genotype G1P8 (26.1%). Genotypes G3P8 represented 11% of samples while G4P8 re-emerged as an important genotype, and was identified in 6% of samples. Uncommon rotavirus G and P combinations continue to be identified, with G2P8 and G9P4 identified during this survey. Differences in genotype distribution based on vaccine usage continue to be evident in Australian states. This survey continues to highlight the fluctuations in rotavirus genotypes, with an annual change in dominant genotypes suggesting a more dynamic wild-type population.
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