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African swine fever (ASF) is an infectious lethal disease affecting domestic pigs and wild boar. For more than a decade ASF infection by genotype IIhas been circulating in Eurasian wild boar populations. It can be transmitted via ...
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African swine fever (ASF) is an infectious lethal disease affecting domestic pigs and wild boar. For more than a decade ASF infection by genotype IIhas been circulating in Eurasian wild boar populations. It can be transmitted via direct animal contact or contact with contaminated carcasses in the environment. After several years of virus circulation in European wild boar population ongoing disease surveillance suggests regional fade-out of the infection. With this study an exit strategy based on routine surveillance procedures had to be informed and tested using an eco-epidemiological spatially explicit individual-based transmission model. The model simulations were performed on the geographical wild boar habitat map of Estonia and analysis referred to the administrative unit level of 2.500 km2 on average (LAU1 units). The analysis addressed the temporal profile of virus- and sero-positive animals in different age cohorts and the abundance of carcasses of animals succumbed to the disease in conjunction with regional virus-fade out. Alternative scenarios were tested for their impact on the duration of virus circulation in a limited area. Finally, different criteria to decide on the final status ASF circulation in a region were tested for their reliability by mimicking routine volumes of passive and active surveillance. The temporal profiles confirm the limited chance of a direct demonstration of virus absence. Therefore, the exit decision requires monitoring periods of several months to years. In order to keep efforts down a two-phase exit protocol does combine a longer phase with routine surveillance (the Screening phase) and a shorter (minimal) phase (the Confirmation phase) with increased surveillance (the maximum possible under field conditions). The two-phase exit strategy facilitates trade-off between invested surveillance efforts and total time to the final decision. Sensitivity of the exit decision is tested for uncertain aspects of ASF epidemiology and revealed performance decrease with increasing natural mortality, but improvement with increasing wild boar density and more distant translocations e.g. due to human activity. Survivors with extreme long-term infectiousness (years), if they would exist, do render the tested exit decision as unreliable. However, there is no evidence in support of such an assumption. Virus attenuation in terms of increased proportion of survivors (up to 20% infected animals) and longer infectious periods (up to 4 weeks post infection) was congruent with the proposed exit strategy. The input to an exit decision by active surveillance i.e. testing of hunted animals, in particular for serology, was negligible.
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African swine fever (ASF) infection is circulating in Eurasia since a decade within wild boar populations without a demonstrated vector host. Further the infection was recurrently translocated by spatio‐temporal dynamics that is ...
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African swine fever (ASF) infection is circulating in Eurasia since a decade within wild boar populations without a demonstrated vector host. Further the infection was recurrently translocated by spatio‐temporal dynamics that is incompatible with wild boar movement characteristics. Management actions are required in areas affected by ASF. Control measures address areas with recent focal introduction and areas with ASF circulating several seasons or endemic occurrence. In view of acknowledged gaps in understanding ecology and epidemiology of ASF in Eurasian wild boar, mechanistic modelling was applied. A comparative assessment of alternative control efforts in the focal situations was performed, considering pre‐emptive hunting, carcass detection and removal as well as fencing of selected zones. The individual‐based model was applied to test whether inclusion of natural barriers would affect the similarity with ADNS notification data when simulating the landscape scale spread in the Baltics and Poland. The tendency of barriers to improve the explicit space‐time predictions of the model could not be proven, more research is needed here. The comparative assessment revealed that in the focal scenario the increasing removal of carcasses will provide the greatest return on investment (given carcasses being involved in the transmission). Culling of the inner zones, usually with ASF detections, should be organised early if biosecurity standards could be guaranteed. Preventive hunting around the zones affected by ASF was an inevitable measure to cope with the risk of undetected release of the infection, although the measure alone was unable to terminate the spread. Fences assumed not wild boar proof contributed only marginally to the success but may act as demarcation of management zones in practice. The focal approach appears useful and practical to address ASF after local introductions.
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African Swine Fever (ASF) is an infectious lethal disease affecting domestic pigs and wild boar. In the EU the infection perpetuates predominantly in wild boar populations. ASF control comprises wild boar population reduction meas...
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African Swine Fever (ASF) is an infectious lethal disease affecting domestic pigs and wild boar. In the EU the infection perpetuates predominantly in wild boar populations. ASF control comprises wild boar population reduction measures,e.g. pre-emptive culling in delineated zones, called white zones (WZ).TheseWZ areplaced geographically adjacent to an area with ASF circulating in wild boar (ASF positive area).The ideal WZ would be depopulated of wild boar without possibility of recolonization. However, WZ may still harbour live wild boar after its establishment and the functionality of the WZ inherently foresees ASF enteringit. But the spread of the infection is expected tostop within an effective WZ. The concept mustnotmatch legislative zones, likewise infected area, Part I, Part II, etc. In order to compare different approaches to implement a WZ(e.g. targets and speed of population reduction in the WZ, width of the WZ, and distance of the WZ from the ASF-positive area), an individual-based spatially explicit model was adjusted to four historic WZ-like situations in the EU, i.e. Estonia 2014, Latvia 2016, Czech Republic 2017, and France 2018. The model was used to simulate the reported spatio-temporal layout and targeted measures. The stochasticity of the model provided understanding of the general efficiency of these WZ. Alternatives of the local measures were simulated as scenarios to identify caveats of the settings and derive improvements in future applications. The simulation outcome suggests issues to be addressed in implementing future WZ: i) distance between ASF-positive area and the WZ was adequate if adapted to the speed of propagation according to the local wild boar density, and the time horizon of depopulation measures envisaged for the WZ; ii) the width of the WZ was adequately set if everywhere it was preventedthat short infection chains already led out of the zone, iii) the WZ around focal introductions was most efficient if depopulated by culling the maximum of a defined (or fenced) population in shortest time with minimal disturbance, for instance, by trapping, sharp shooting or using silencers.Aspects of density, timing and spatial distribution in relation to the efficiency of WZ layout are explored.
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Structural mutants of p53 induce global p53 protein destabilization and misfolding, followed by p53 protein aggregation. First evidence indicates that p53 can be part of protein condensates and that p53 aggregation potentially tra...
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Structural mutants of p53 induce global p53 protein destabilization and misfolding, followed by p53 protein aggregation. First evidence indicates that p53 can be part of protein condensates and that p53 aggregation potentially transitions through a condensate-like state. We show condensate-like states of fluorescently labeled structural mutant p53 in the nucleus of living cancer cells. We furthermore identified small molecule compounds that interact with the p53 protein and lead to dissolution of p53 structural mutant condensates. The same compounds lead to condensation of a fluorescently tagged p53 DNA-binding mutant, indicating that the identified compounds differentially alter p53 condensation behavior depending on the type of p53 mutation.In contrast to p53 aggregation inhibitors, these compounds are active on p53 condensates and do not lead to mutant p53 reactivation. Taken together our study provides evidence for structural mutant p53 condensation in living cells and tools to modulate this process.
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Spatial spread and maintenance of foot‐and‐mouth disease virus infections in wildlife populations of Thrace region applying epidemiological modelling.
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We consider the model checking problem for Hybrid Logic. Known algorithms so far are global in the sense that they compute, inductively, in every step the set of all worlds of a Kripke structure that satisfy a subformula of the in...
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We consider the model checking problem for Hybrid Logic. Known algorithms so far are global in the sense that they compute, inductively, in every step the set of all worlds of a Kripke structure that satisfy a subformula of the input. Hence, they always exploit the entire structure. Local model checking tries to avoid this by only traversing necessary parts of the input in order to establish or refute the satisfaction relation between a given world and a formula. We present a framework for local model checking of Hybrid Logic based on games. We show that these games are simple reachability games for ordinary Hybrid Logic and weak Buchi games for Hybrid Logic with operators interpreted over the transitive closure of the accessibility relation of the underlying Kripke frame, and show how to solve these games thus solving the local model checking problem. Since the first-order part of Hybrid Logic is inherently hard to localise in model checking, we give examples, in the end, of how global model checkers can be optimised in certain special cases using well-established techniques like fixpoint approximations and divide-and-conquer algorithms.
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摘要 :
African Swine Fever (ASF) is an infectious lethal disease affecting domestic pigs and wild boar. In the EU the infection perpetuates predominantly in wild boar populations. ASF control comprises wild boar population reduction meas...
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African Swine Fever (ASF) is an infectious lethal disease affecting domestic pigs and wild boar. In the EU the infection perpetuates predominantly in wild boar populations. ASF control comprises wild boar population reduction measures, e.g. pre-emptive culling in delineated zones, called white zones (WZ). These WZ are placed geographically adjacent to an area with ASF circulating in wild boar (ASF positive area). The ideal WZ would be depopulated of wild boar without possibility of recolonization. However, live wild boar may still be present in the WZ after its implementation and the functionality of the WZ inherently foresees ASF entering it. But the spread of the infection is expected to stop within an effective WZ. The principal approach was established in the EU with regards to focal introductions. Here the special case is considered when the WZ approach is applied adjacent to an (potentially large) area with limited ASF control. The results of the spatially explicit individual-based simulations in different EU landscapes demonstrate that the WZ strategy becomes more complicated when applied in adjacency to areas with limited control. The failure rate and the hunting effort to implement the WZ increases compared to the focal scenario. The three WZ parameters, width, distance to core area and culling target density are tested in both situations and combined with carcass removal and fencing to facilitate effect comparison. Proactive approaches are simulated and the outcome was found to be dominated from the landscape and/or the WZ parameters chosen.
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We consider hybridisations of the full branching time logicCTL⁎and its prominent fragments CTL,CTL+andFCTL+through the addition of nominals, binders and jumps. We formally define three types of hybridisations by restricting the i...
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We consider hybridisations of the full branching time logicCTL⁎and its prominent fragments CTL,CTL+andFCTL+through the addition of nominals, binders and jumps. We formally define three types of hybridisations by restricting the interplay between hybrid operators and path formulas contrary to previous proposals in the literature which ignored potential problems with a formal semantics. We then investigate the model checking problem for these logics obtaining expression complexities fromPSpace-completeness to non-elementary decidability and data complexities ranging fromNLogSpacetoPSpace. Lastly, we identify a family of fragments of these hybrid logics, called the bounded fragments, that (in some cases) have the same model checking complexity as their non-hybrid counterparts.
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We investigated the fragmentation of SF_6~(n+) (n≥2) produced by impact of 2 MeV He~(2+) ions on neutral SF_6. single time-of-flight spectra of the resulting fragment ions were acquired with special interest in molecular dication...
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We investigated the fragmentation of SF_6~(n+) (n≥2) produced by impact of 2 MeV He~(2+) ions on neutral SF_6. single time-of-flight spectra of the resulting fragment ions were acquired with special interest in molecular dications, as well as coincident time-of-flight spectra of two ions arising from the same parent molecule, both flight time measurements being triggered by projectiles scattered in forward direction. Momentum correlations derived from the time-of-flight spectra allowed us to give a detailed description of the dynamics of the underlying fragmentation processes. Kinetic energy distributions of fragments and fragment pairs were calculated from the time-of-flight peaks by a novel method using a regularisation algorithm. In order to obtain a detailed picture of the fragmentation process, ab initio calculations of the vertical double-ionisation potentials in the valence region as well as the dissociation energies for all relevant fragmentation channels were performed. the combination of experimental and computational data allowed us to correlate initial electronic states of the doubly ionised parent molecule with the resulting fragmentation channels and to explain their relative abundances in the spectra.
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Discrete Interval Encoding Trees are data structures for the representation of fat, i.e. densely populated sets over a discrete linear order. In this paper, we introduce algorithms for set-theoretic operations like intersection, u...
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Discrete Interval Encoding Trees are data structures for the representation of fat, i.e. densely populated sets over a discrete linear order. In this paper, we introduce algorithms for set-theoretic operations like intersection, union, etc. on sets represented as balanced diets. We empirically analyse their performance and show that these algorithms can outperform previously known algorithms on sets, such as the ones implemented in OCaml's standard library.
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