A comprehensive investigation into the effect of vertical component of ground motion on response of sliding unanchored blocks

This study aims to quantify the effect of the vertical component of ground motion on the seismic response of sliding rigid blocks, in terms of maximum and residual displacements. A multi-stripe analysis approach is employed to examine the response with and without the vertical component under various levels of ground motion intensity. First, a parametric study is conducted using a Coulomb friction model with a constant coefficient of friction that does not account for any dependence of the friction coefficient on velocity or pressure. It is shown that the effect of the vertical component on maximum and residual displacement is more pronounced for ground motions that can barely initiate sliding. Moreover, the influence of the vertical component on the residual sliding displacement is higher than that on the maximum displacement. Subsequently, to account for the friction coefficient dependence on pressure and sliding velocity, two interface cases (steel-steel, and concrete-concrete) are analyzed. It is found that even when a variable coefficient of friction is used, the overall trends observed for a constant coefficient of friction do not change.ISSN:0141-029

Getting Chip Card Payments Right

EMV is the international protocol standard for smart card payments and is used in billions of payment cards worldwide. Despite the standard's advertised security, various issues have been previously uncovered, deriving from logical flaws that are hard to spot in EMV's lengthy and complex specification. We have formalized various models of EMV in Tamarin, a symbolic model checker for cryptographic protocols. Tamarin was extremely effective in finding critical flaws, both known and new, and in many cases exploitable on actual cards. We report on these past problems as well as followup work where we verified the latest, improved version of the protocol, the EMV kernel C8. This work puts C8's correctness on a firm, formal basis, and clarifies which guarantees hold for C8 and under which assumptions. Overall our work supports the thesis that cryptographic protocol model checkers like Tamarin have an essential role to play in improving the security of real-world payment protocols and that they are up to this challenge.ISSN:0302-9743ISSN:1611-334

Molecular epidemiology of Cercospora leaf spot on resistant and susceptible sugar beet hybrids

Cercospora leaf spot (CLS), caused by Cercospora beticola, is a major foliar disease impacting sugar beet production worldwide. The development of new resistant sugar beet hybrids is a powerful tool to better manage the disease, but it is unclear how these hybrids affect CLS epidemiology. We used a molecular epidemiology approach to study natural epidemics of CLS affecting two susceptible and two resistant sugar beet hybrids at two field sites. Infected plants were geotagged on a weekly basis. Isolations of C. beticola were made from infected leaves and genotyped using six simple-sequence repeat loci to identify clones. We determined that CLS epidemics had a later onset in plots planted to resistant hybrids, but once the pathogen established an infection, there was little difference between resistant and susceptible hybrids in the probability of localized spread and dispersal. We found that different clones often infected the same leaf and that clusters of infected plants were often colonized by a mixture of clones. There was little overall difference in genetic diversity of C. beticola collected on resistant and susceptible hybrids; however, genotypic diversity was lower on the resistant hybrid at one site, suggestive of a selection bottleneck. At the end of the epidemic infections were not randomly distributed across the fields and we found that a single clone could spread over a distance of 100 m during a growing season.ISSN:0032-0862ISSN:1365-305

Empirical approximation of the gaussian distribution in Rᵈ

ISSN:0001-8708ISSN:1090-208

Upper and lower crustal deformation and residual topography in a continental back-arc: Inferences from the Pannonian-Transylvanian Basins

The topography and subsidence history of sedimentary basins are commonly related to crustal and lithospheric thinning linked to isostasy, also influenced by flexure and dynamic topography. The static component of the topography relative to a reference level can be calculated by the assumption that a lithospheric column consisting of crustal layers and a lithospheric mantle lid float within the asthenosphere. Here, we discuss the observed and calculated residual topography of the Pannonian Basin, i.e. the difference between the actual and calculated isostatic topography. The residual topography calculation is based on new geophysical constraints on the sedimentary, upper and lower crustal and lithospheric thicknesses based on reflection seismic and new receiver function analysis. The crustal thickness decreases from 40 to 45 km beneath the Eastern Alps to 22 km in the eastern Great Hungarian Plain that is floored by less than 60 km thick lithosphere affected by Miocene extension. The sedimentary thickness reaches more than 6 km in the deepest depocenters. The crust is much less attenuated in the Transdanubian Range (28 km), Apuseni Mountains or Transylvanian Basin (32.5–35 km). The interpreted lower crustal thickness reaches maximum 15–20 km in the Eastern Alps, 12–15 km in the Apuseni Mountains, 10 km in the Transdanubian Range and thins to 5 km in the Great Hungarian Plain. The new four-layer lithospheric model shows a much lower residual topography value than previously suggested for the Pannonian Basin. Only the Transdanubian Range is affected by maximum 300 m of positive residual topography, whereas the Transylvanian Basin shows 300–400 m of negative residual topographic values. The former is interpreted to be affected by small-scale asthenospheric upwelling effects, likely also contributing to the Miocene-Pliocene volcanic activity of the area. While the currently uplifting Transylvanian Basin undergoes tectonic re-adjustment linked to the gradual Vrancea slab break-off. Our results demonstrate the important effects of the thick sedimentary succession and the different crustal thinning values on the observed and predicted topographic variations in extensional sedimentary basins.ISSN:0040-1951ISSN:1879-326

Ferric carboxymaltose with or without phosphate substitution in iron deficiency or iron deficiency anemia before elective surgery – The DeFICIT trial

Background: Iron deficiency anemia in the perioperative setting is treated predominantly with intravenous iron formulation, of which ferric carboxymaltose may induce hypophosphatemia by modulating fibroblast growth factor 23. Methods: In this single-center, prospective, randomized, double-blind trial, we consented 92 adult patients scheduled for elective major abdominal or thoracic surgery. These patients either had isolated iron deficiency (plasma ferritin <100 ng/mL or transferrin saturation < 20 %) or iron deficiency anemia (hemoglobin (Hb) 100–130 g/L with plasma ferritin <100 ng/mL or transferrin saturation < 20 %). Preoperatively, participants received a single preoperative intravenous dose of ferric carboxymaltose and were then randomly assigned to receive either phosphate or placebo, administered orally three times a day for 30 days corresponding to an 18 mmol dose of daily phosphate supplementation in the intervention group. The primary endpoint was the minimum serum phosphate concentration during follow-up visits. The key secondary efficacy endpoint was mean perioperative hemoglobin concentration of postoperative days 0, 2 and 4, assessing the non-inferiority of additional phosphate supplementation. Results: We randomly consented 46 patients in each group (mean ± SD age 56 ± 17 years, 57 % female). Minimal phosphate concentration was 0.49 ± 0.21 mmol/L in the treatment group and 0.42 ± 0.17 mmol/L in the placebo group (p = 0.12, two-sided p-value). Average mean hemoglobin was 110 ± 16 g/L in the treatment and 113 ± 13 g/L in the placebo group (p = 0.023, one-sided p-value for non-inferiority). Hypophosphatemia occurred in 32 patients (70 %) of the treatment group and in 39 patients (85 %) of the placebo group (odds ratio 0.15, 95 % CI from 0.02 to 0.77, p = 0.014). Secondary outcomes, such as rescue medication use, core muscle strength and MOCA test scores, did not differ between groups. Conclusion: Co-administration of oral phosphate supplementation to ferric carboxymaltose cannot prevent hypophosphatemia. However, hypophosphatemia occurs in fewer patients. Phosphate co-administration did not impede the treatment of iron deficiency anemia with ferric carboxymaltose.ISSN:0952-8180ISSN:1873-452

Temperate grasslands under climate extremes: Effects of plant diversity on ecosystem services

Temperate grasslands provide a broad set of ecosystem services (ES), which include both provisioning ES (e.g., yield production) and non-provisioning ES (e.g., soil carbon sequestration, weed suppression, aesthetics, recreation). Yet, ES can considerably decrease under climate extremes, potentially threatening grassland ES in the future. Meanwhile, some grassland ES were shown to increase with increasing plant diversity. However, whether plant diversity can mitigate the effects of extreme climate events on multiple ES is still unclear, as past studies frequently focused on a single ES, namely aboveground biomass production (AGB). Therefore, we conducted a systematic literature review to identify the potential mitigation effect of plant species richness against the impact of extreme drought and heat stress on multiple ES in temperate C3 grasslands, by synthesizing existing knowledge and identifying research gaps. Since the 1900s, the number of studies on plant diversity and grassland ES has increased. However, only few studies also addressed climatic extremes, despite a ten-fold increase of studies in the last two decades. Moreover, while all studies included in this review (n=31; 26 biodiversity experiments (sown and weeded), five on-farm studies) addressed provisioning ES (AGB), only 45 % of the studies investigated non-provisioning ES such as climate regulation or weed suppression. No study considered cultural ES. Overall, the positive effect of higher plant species richness on grassland provisioning ES persisted also under extreme conditions, despite reducing absolute magnitudes of ES. Since the number of studies per specific non-provisioning ES was small (n = 2 on average), the general effect of plant species richness acting as insurance against climate extremes for those ES remain largely unknown. In addition, we assessed four different indices commonly used to study biodiversity–ES relationships, but no best index for resistance, recovery, and resilience of ES against climate extremes was found. Overall, the existing evidence reviewed here suggests that maintaining or increasing plant diversity in temperate grasslands can indeed be considered as a natural insurance against current and future climate risks for AGB. However, for any non-provisioning ES, currently available research is too scarce to conclude such a mitigation effect. Closing this research gap, particularly for on-farm settings, could help advance policy and societal support for sustainable, climate change-adapted grassland management.ISSN:0167-8809ISSN:1873-230