The Replicase Gene of Avian Coronavirus Infectious Bronchitis Virus Is a Determinant of Pathogenicity

We have previously demonstrated that the replacement of the S gene from an avirulent strain (Beaudette) of infectious bronchitis virus (IBV) with an S gene from a virulent strain (M41) resulted in a recombinant virus (BeauR-M41(S)) with the in vitro cell tropism of the virulent virus but that was still avirulent. In order to investigate whether any of the other structural or accessory genes played a role in pathogenicity we have now replaced these from the Beaudette strain with those from M41. The recombinant IBV was in effect a chimaeric virus with the replicase gene derived from Beaudette and the rest of the genome from M41. This demonstrated that it is possible to exchange a large region of the IBV genome, approximately 8.4 kb, using our transient dominant selection method. Recovery of a viable recombinant IBV also demonstrated that it is possible to interchange a complete replicase gene as we had in effect replaced the M41 replicase gene with the Beaudette derived gene. Analysis of the chimaeric virus showed that it was avirulent indicating that none of the structural or accessory genes derived from a virulent isolate of IBV were able to restore virulence and that therefore, the loss of virulence associated with the Beaudette strain resides in the replicase gene

Geographica Helvetica / Spatial and temporal variability of sediment transfer and storage in an Alpine basin (Reintal valley, Bavarian Alps, Gemany)

This paper focuses in particular on clastic sediment fluxes on talus slopes. Using orthophoto interpretation, field measurements and GIS-techniques, a quantification of areas and volumes of active sediment transfer related to specific landform units was achieved for different spatial scales. Closer investigation of a single landform complex, more specifically a talus sheet/ debris cone-complex, brought to light that remobilisation can overbalance sediment input by a factor of 57. This could be an indication of what may be expected in the whole catchment. At present. approximately 9% of the research area (3 km2), comprising talus slopes and valley bottom, is characterised by sediment transfer mainly through gravilational and fluvial processes. A comparison of the vast volumes (117.174 m3) derived from these active areas of recent sediment transfer and the volume of the entire valley fill (0.07 km3) indicates, however, that the largest part must be related to remobilised sediments and cannot be considered as sediment input from the adjacent rockwalls. This conclusion is also supported by direct measurements of sediment input.(VLID)221354

Decadal-scale changes of the Ödenwinkelkees, Central Austria, suggest increasing control of topography and evolution towards steady state

Small mountain glaciers have short mass balance response times to climate change and are consequently very important for short-term contributions to sea level. However, a distinct research and knowledge gap exists between (1) wider regional studies that produce overview patterns and trends in glacier changes, and (2) in situ local scale studies that emphasise spatial heterogeneity and complexity in glacier responses to climate. This study of a small glacier in central Austria presents a spatiotemporally detailed analysis of changes in glacier geometry and changes in glaciological behaviour. It integrates geomorphological surveys, historical maps, aerial photographs, airborne LiDAR data, ground-based differential global positioning surveys and Ground Penetrating Radar surveys to produce three-dimensional glacier geometry at 13 time increments spanning from 1850 to 2013. Glacier length, area and volume parameters all generally showed reductions with time. The glacier equilibrium line altitude increased by 90 m between 1850 and 2008. Calculations of the mean bed shear stress rapidly approaching less than 100 kPA, of the volume-area ratio fast approaching 1.458, and comparison of the geometric reconstructions with a 1D theoretical model could together be interpreted to suggest evolution of the glacier geometry towards steady state. If the present linear trend in declining ice volume continues, then the Ödenwinkelkees will disappear by the year 2040, but we conceptualise that non-linear effects of bed overdeepenings on ice dynamics, of supraglacial debris cover on the surface energy balance, and of local topographically driven controls, namely wind-redistributed snow deposition, avalanching and solar shading, will become proportionally more important factors in the glacier net balance

Bacterial Genetic Fingerprint: a Reliable Factor in the Study of the Epidemiology of Human Campylobacter Enteritis?

The rate of human intestinal infections with more than a single Campylobacter strain was determined and the genetic variabilities of Campylobacter strains throughout an infection episode were investigated by means of pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR). For 48 and 49 of 50 patients, all isolates from one sample showed identical patterns by PFGE and ERIC-PCR, respectively. Throughout an infection episode in 47 of 52 patients, the PFGE fingerprints of the isolates remained stable, while in 1 patient two different species were observed and in 4 patients different patterns were observed. Therefore, ERIC-PCR proved less discriminative than PFGE. These findings suggest that human infection with more than one Campylobacter strain is rare and should not significantly impair epidemiologic analyses. However, changes in the genetic fingerprint throughout an infection should be considered in the assessment of epidemiologic studies of Campylobacter spp

An Inventory of Proglacial Systems in Austria, Switzerland and Across Patagonia

Deglaciation since the Little Ice Age has exposed only a small areal proportion of alpine catchments, but these proglacial systems are disproportionately important as sediment sources. Indeed sediment yields from proglacial rivers are amongst the highest measured anywhere in the World. Motivated by a desire to understand where exactly within catchments this sediment is coming from and how it might evolve, this chapter presents the first digital inventories of proglacial systems and the first comparative inter- and intra-catchment comparison of their geometry, topography and geomorphology. Whilst focussing on the description of these inventories and on descriptive statistics, it highlights the potential of these data, with examples from Austria, Switzerland and Patagonia, for interpreting landscape evolution status, predominant earth surface processes and glacial meltwater inundation patterns. Switzerland has by far the highest proportion of very small (<0.5 km2) proglacial systems. Patagonia has the most even distribution of proglacial systems in terms of areal size and elevation above sea level. We found no east–west or north–south spatial pattern in geometric or topographical metrics, such as hypsometric index, thereby refuting a straightforward control of climate-driven precipitation or air temperature. However, we note that geology, particularly rock hardness, could be a major factor in proglacial system character. Likely sediment sinks can occupy up to c. 30 and 20% of proglacial systems in Austria and Switzerland, respectively, but up to 90% of those in Patagonia where many systems terminate on a coastline. Meltwater influence maps and landform maps, derived from contributing area and slope data, respectively, will not only be useful for many environmental science disciplines but also for water resources, landscape managers and natural hazards authorities. Overall, this chapter presents an objective and easily implemented method for making proglacial systems inventories and for characterising inter- and intra-catchment geomorphological form and function

Antiviral activity of selected cathelicidins against infectious bronchitis virus

Avian infectious bronchitis (IB) is a highly contagious disease caused by infectious bronchitis virus (IBV), a coronavirus of domestic fowl. IB is a major concern in the poultry industry, causing worldwide economic losses through decreased egg production and quality and by increasing the chicken's susceptibility for secondary bacterial infections, particularly Escherichia coli. In this study, the anti-IBV activity of cathelicidins, small antimicrobial peptides of the innate immune system was investigated. The cell culture adapted (nonvirulent) IBV strain Beaudette was effectively inhibited by the human cathelicidin LL-37 in bovine hamster kidney-21 cells at nontoxic concentrations. The peptide needed to be present during virus inoculation to effectively inhibit the infection of IBV-Beaudette, indicating that LL-37 likely bound viral particles. However, no clear morphological changes in the IBV virion upon binding were observed by electron microscopy. In this cell culture model, chicken cathelicidins (CATH1-3) were inactive against IBV-Beaudette. In contrast, in multicellular infection models using the virulent IBV-M41 strain the activities of human and chicken cathelicidins were different. In particular, upon inoculation of 10-day-old embryonic eggs with IBV-M41, CATH-2 reduced the viral load to a higher extend than LL-37. Similarly, viral infection of chicken tracheal organ cultures with IBV-M41 was significantly reduced in the presence of CATH-2 but not LL-37. These results indicate a potential antiviral role for CATH-2 upon IBV infection in vivo