Results from a three year testing project of new strawberry cultivars in Verticillium infested soils and under organic farming conditions

As part of a research project 13 cultivars were planted in 2005 at 11 sites on 9 farms in 5 different Austrian regions. The aim was to find new cultivars tolerant to soil-borne pathogens and leaf/fruit diseases, with high yield, winter hardness and good fruit quality, to serve as alternative to the highly susceptible cultivar ‘Elsanta’, regarding soil-borne diseases. Plant vigour and infestation with Verticillium dahliae and leaf diseases were evaluated in 2005 und 2006 at 7 sites and in 2007 at 3 sites. In addition, following parameters were assessed on 2 organically managed sites in 2006 and 2007: marketable yield, percentage of different categories of unmarketable fruits and incidence of the blossom weevil. In 2006 fruit characteristics and consumer acceptance were studied. ‘Elsanta’ showed the highest infestation with V. dahliae whereas ‘Salsa’, ‘Daroyal’ and ‘Alice’ were most tolerant. ‘Dora’, ‘Eva’, ‘Queen Elisa’ and ‘Daroyal’ recorded significantly higher losses by the blossom weevil than ‘Alice’. ‘Alba’ and ‘Divine’ were the earliest cultivars in ripening time. Highest marketable yield per plant had the late ripening cultivars, particularly ‘Salsa’ and ‘Sonata’. Of all early ripening cultivars tested, ‘Elsanta’ showed the highest productivity, followed by 'Alba', ‘Darselect’, ‘Daroyal’ and ‘Eva’. Regarding fruit firmness, content of ascorbic acid, shelf life and appearance, ‘Alba’, ’Clery’, ‘Eva’ and ‘Queen Elisa’ were most convincing. The best tasting cultivars were ‘Clery’, ‘Daroyal’ and ‘Divine’. Summing up all the results, ‘Alba’, ‘Alice’ and ‘Salsa’ can be recommended for organic production, whereas ‘Clery’, ‘Daroyal’, ‘Darselect’, ‘Elsanta’, ‘Eva’, ‘Queen Elisa’ and ‘Sonata’ are classified as suitable for only a limited extent. ‘Elsanta’, ‘Divine’, ‘Dora’ and ‘Sonata’ are particularly unsuitable for growing in Verticillium infested soils. ‘Divine’, ‘Dora’, and ‘Record’ cannot be recommended for organic production at all

Lösungsansätze für Nachbauprobleme durch bodenbürtige Pathogene im biologischen Erdbeeranbau

Soil-borne pathogens, above all Verticillium sp. cause plant losses and yield decreases in many Austrian strawberry fields, also in organic farming systems; in a research project possibilities to resolve this problem were examined. In a field trial, which was started 1998, organically managed and differently fertilized plots (green compost, manure, hornchips) were compared to an unfertilised control plot and to two mineral fertilized and conventionally treated plots; the differences in field characteristics of strawberries in 2004 and 2005 were low, but differences in storage and biochemical characteristics could be seen in 2005. Some new cultivars tested as alternative to the very sensitive 'Elsanta' planted in 2005 on several farms showed a higher tolerance to diseases and good yield and fruit quality characteristics. Brassica sp. planted as an intercrop before strawberries reduced the amount of microsclerotia of Verticillium dahliae in highly infested soils, nevertheless the system has to be optimised and adapted to our climatic and husbandry conditions in further trials

Possible solutions for replant problems caused by soil-borne pathogens in organic strawberry production

Soil-borne pathogens, above all Verticillium sp. cause plant losses and yield decreases in many Austrian strawberry fields, also in organic farming systems; in a research project possibilities to resolve this problem were examined. In a field trial, which was started 1998, organically managed and differently fertilized plots (green compost, manure, hornchips) were compared to an unfertilised control plot and to two mineral fertilized and conventionally treated plots; the differences in field characteristics of strawberries in 2004 and 2005 were low, but differences in storage and biochemical characteristics could be seen in 2005. Some new cultivars tested as alternative to the very sensitive 'Elsanta' planted in 2005 on several farms showed a higher tolerance to diseases and good yield and fruit quality characteristics. Brassica sp. planted as an intercrop before strawberries reduced the amount of microsclerotia of Verticillium dahliae in highly infested soils, nevertheless the system has to be optimised and adapted to our climatic and husbandry conditions in further trials

Bordetella pertussis Infection Exacerbates Influenza Virus Infection through Pertussis Toxin-Mediated Suppression of Innate Immunity

Pertussis (whooping cough) is frequently complicated by concomitant infections with respiratory viruses. Here we report the effect of Bordetella pertussis infection on subsequent influenza virus (PR8) infection in mouse models and the role of pertussis toxin (PT) in this effect. BALB/c mice infected with a wild-type strain of B. pertussis (WT) and subsequently (up to 14 days later) infected with PR8 had significantly increased pulmonary viral titers, lung pathology and mortality compared to mice similarly infected with a PT-deficient mutant strain (ΔPT) and PR8. Substitution of WT infection by intranasal treatment with purified active PT was sufficient to replicate the exacerbating effects on PR8 infection in BALB/c and C57/BL6 mice, but the effects of PT were lost when toxin was administered 24 h after virus inoculation. PT had no effect on virus titers in primary cultures of murine tracheal epithelial cells (mTECs) in vitro, suggesting the toxin targets an early immune response to increase viral titers in the mouse model. However, type I interferon responses were not affected by PT. Whole genome microarray analysis of gene expression in lung tissue from PT-treated and control PR8-infected mice at 12 and 36 h post-virus inoculation revealed that PT treatment suppressed numerous genes associated with communication between innate and adaptive immune responses. In mice depleted of alveolar macrophages, increase of pulmonary viral titers by PT treatment was lost. PT also suppressed levels of IL-1β, IL-12, IFN-γ, IL-6, KC, MCP-1 and TNF-α in the airways after PR8 infection. Furthermore PT treatment inhibited early recruitment of neutrophils and NK cells to the airways. Together these findings demonstrate that infection with B. pertussis through PT activity predisposes the host to exacerbated influenza infection by countering protective innate immune responses that control virus titers

Penetration of interferometric radar signals in Antarctic snow

Synthetic aperture radar interferometry (InSAR) is an efficient technique for mapping the surface elevation and its temporal change over glaciers and ice sheets. However, due to the penetration of the SAR signal into snow and ice, the apparent elevation in uncorrected InSAR digital elevation models (DEMs) is displaced versus the actual surface. We studied relations between interferometric radar signals and physical snow properties and tested procedures for correcting the elevation bias. The work is based on satellite and in situ data over Union Glacier in the Ellsworth Mountains, West Antarctica, including interferometric data of the TanDEM-X mission, topographic data from optical satellite sensors and field measurements on snow structure, and stratigraphy undertaken in December 2016. The study area comprises ice-free surfaces, bare ice, dry snow and firn with a variety of structural features related to local differences in wind exposure and snow accumulation. Time series of laser measurements of NASA's Ice, Cloud and land Elevation Satellite (ICESat) and ICESat-2 show steady-state surface topography. For area-wide elevation reference we use the Reference Elevation Model of Antarctica (REMA). The different elevation data are vertically co-registered on a blue ice area that is not affected by radar signal penetration. Backscatter simulations with a multilayer radiative transfer model show large variations for scattering of individual snow layers, but the vertical backscatter distribution can be approximated by an exponential function representing uniform absorption and scattering properties. We obtain estimates of the elevation bias by inverting the interferometric volume correlation coefficient (coherence), applying a uniform volume model for describing the vertical loss function. Whereas the mean values of the computed elevation bias and the elevation difference between the TanDEM-X DEMs and the REMA show good agreement, a trend towards overestimation of penetration is evident for heavily wind-exposed areas with low accumulation and towards underestimation for areas with higher accumulation rates. In both cases deviations from the uniform volume structure are the main reason. In the first case the dense sequence of horizontal structures related to internal wind crust, ice layers and density stratification causes increased scattering in near-surface layers. In the second case the small grain size of the top snow layers causes a downward shift in the scattering phase centre.</p

Changing pattern of ice flow and mass balance for glaciers discharging into the Larsen A and B embayments, Antarctic Peninsula, 2011 to 2016

We analysed volume change and mass balance of outlet glaciers on the northern Antarctic Peninsula over the periods 2011 to 2013 and 2013 to 2016, using high-resolution topographic data from the bistatic interferometric radar satellite mission TanDEM-X. Complementary to the geodetic method that applies DEM differencing, we computed the net mass balance of the main outlet glaciers using the mass budget method, accounting for the difference between the surface mass balance (SMB) and the discharge of ice into an ocean or ice shelf. The SMB values are based on output of the regional climate model RACMO version 2.3p2. To study glacier flow and retrieve ice discharge we generated time series of ice velocity from data from different satellite radar sensors, with radar images of the satellites TerraSAR-X and TanDEM-X as the main source. The study area comprises tributaries to the Larsen A, Larsen Inlet and Prince Gustav Channel embayments (region A), the glaciers calving into the Larsen B embayment (region B) and the glaciers draining into the remnant part of the Larsen B ice shelf in Scar Inlet (region C). The glaciers of region A, where the buttressing ice shelf disintegrated in 1995, and of region B (ice shelf break-up in 2002) show continuing losses in ice mass, with significant reduction of losses after 2013. The mass balance numbers for the grounded glacier area of region A are −3.98 ± 0.33 Gt a−1 from 2011 to 2013 and −2.38 ± 0.18 Gt a−1 from 2013 to 2016. The corresponding numbers for region B are −5.75 ± 0.45 and −2.32 ± 0.25 Gt a−1. The mass balance in region C during the two periods was slightly negative, at −0.54 ± 0.38 Gt a−1 and −0.58 ± 0.25 Gt a−1. The main share in the overall mass losses of the region was contributed by two glaciers: Drygalski Glacier contributing 61 % to the mass deficit of region A, and Hektoria and Green glaciers accounting for 67 % to the mass deficit of region B. Hektoria and Green glaciers accelerated significantly in 2010–2011, triggering elevation losses up to 19.5 m a−1 on the lower terminus during the period 2011 to 2013 and resulting in a mass balance of −3.88 Gt a−1. Slowdown of calving velocities and reduced calving fluxes in 2013 to 2016 coincided with years in which ice mélange and sea ice cover persisted in proglacial fjords and bays during summer

Changing pattern of ice flow and mass balance for glaciers discharging into the Larsen A and B embayments, Antarctic Peninsula, 2011 to 2016

We analysed volume change and mass balance of outlet glaciers on the northern Antarctic Peninsula over the periods 2011 to 2013 and 2013 to 2016, using highresolution topographic data from the bistatic interferometric radar satellite mission TanDEM-X. Complementary to the geodetic method that applies DEM differencing, we computed the net mass balance of the main outlet glaciers using the mass budget method, accounting for the difference between the surface mass balance (SMB) and the discharge of ice into an ocean or ice shelf. The SMB values are based on output of the regional climate model RACMO version 2.3p2. To study glacier flow and retrieve ice discharge we generated time series of ice velocity from data from different satellite radar sensors, with radar images of the satellites TerraSAR-X and TanDEM-X as the main source. The study area comprises tributaries to the Larsen A, Larsen Inlet and Prince Gustav Channel embayments (region A), the glaciers calving into the Larsen B embayment (region B) and the glaciers draining into the remnant part of the Larsen B ice shelf in Scar Inlet (region C). The glaciers of region A, where the buttressing ice shelf disintegrated in 1995, and of region B (ice shelf break-up in 2002) show continuing losses in ice mass, with significant reduction of losses after 2013. The mass balance numbers for the grounded glacier area of region A are -3.98±0.33 Gt a-1 from 2011 to 2013 and -2.38±0.18 Gt a-1 from 2013 to 2016. The corresponding numbers for region B are -5.75±0.45 and -2.32±0.25 Gt a-1. The mass balance in region C during the two periods was slightly negative, at -0.54±0.38 Gt a-1 and -0.58±0.25 Gt a-1. The main share in the overall mass losses of the region was contributed by two glaciers: Drygalski Glacier contributing 61% to the mass deficit of region A, and Hektoria and Green glaciers accounting for 67% to the mass deficit of region B. Hektoria and Green glaciers accelerated significantly in 2010-2011, triggering elevation losses up to 19.5ma-1 on the lower terminus during the period 2011 to 2013 and resulting in a mass balance of -3.88 Gt a-1. Slowdown of calving velocities and reduced calving fluxes in 2013 to 2016 coincided with years in which ice mélange and sea ice cover persisted in proglacial fjords and bays during summer

International collaborative study on the 3rd WHO International Standard for hepatitis B surface antigen

AbstractBackgroundThe WHO International Standard (IS) for hepatitis B surface antigen (HBsAg) is used to standardize HBsAg assays. Stocks of the 2nd IS for HBsAg are depleted. The proposal to establish its replacement was endorsed by WHO in 2012.ObjectivePreparation of a freeze-dried candidate 3rd IS (NIBSC 12/226); evaluation of its suitability in a WHO international collaborative study; calibration of its potency in International Units (IU).Study designThe 3rd IS is based on plasma-derived, purified, inactivated HBsAg from Vietnam. Qualitative and quantitative HBsAg assays were used to evaluate 12/226 alongside the 2nd IS and 1st IS. Blinded study samples included a duplicate of 12/226, a negative control and two diluted plasma samples representing hepatitis B virus (HBV) genotypes A and B.ResultsTwelve laboratories from 9 countries returned 22 data sets from 15 methods. The overall geometric mean potency of 12/226 is 47.3IU/mL (±13% CV) when compared to the 2nd IS with HBV subgenotype A2. The 3rd IS has HBV subgenotype B4 with a heterogeneous HBsAg subtype population of ayw1 and adw2. Some genotype-dependent effects on the inter-laboratory variability were observed but overall mean potencies were virtually identical irrespective of the IS used for calibration. Stability studies indicate that the candidate is stable for long-term use.Conclusions12/226 was established in October 2014 by the WHO Expert Committee on Biological Standardization as the 3rd IS for HBsAg with a potency of 47.3IU per ampoule maintaining the continuity in the standardization of HBsAg assays