| 1. |
- Milberg, Per, et al.
(författare)
-
A burning desire for smoke? Sampling insects favoured by forestfire in the absence of fire
- 2015
-
Ingår i: Journal of Insect Conservation. - : Springer. - 1366-638X .- 1572-9753. ; 19:1, s. 55-65
-
Tidskriftsartikel (refereegranskat)abstract
- Fire-favoured insects are difficult to sampleexcept opportunistically after forest fires. Here, we tested ifsmoke from a small fire could be an efficient way to samplesuch insects. Insects were sampled over ca. 10 h hours, byhand-picking and netting on screens put up around the fire.Two specimens of the rare and redlisted Hormopeza spp.(Diptera, Empididae) were caught. Large numbers([20,000) of Microsania spp. (Diptera, Platypezidae) werecaught, but none in the absence of smoke. The numbers ofMicrosania spp. clearly peaked in late afternoon, and ashort sampling period would be sufficient if targeting onlythis taxon. Of the almost 200 species of Coleoptera, 17 %were considered as fire-favoured, contributing 9 % of thespecimens, suggesting low efficiency of the method for thisgroup. Using 23 sites differing in fire history, catches ofMicrosania spp. were unaffected by numbers and area offorest fire (preceding 5 years and within 10 km radius overthe sampling sites). In contrast, there was a weak trend forthe proportion of fire-favoured Coleoptera to increase withincreasing number of fires. To conclude, smoke as producedin our study can clearly attract fire-favoured Diptera,but smoke had only a weak effect on fire-favoured Coleopterain the study area. It is still likely that selectivelypicking specimens of species attracted to smoke is a morecost-efficient method than using, e.g., Malaise traps thatcatch indiscriminately.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Abidi, Hani, et al.
(författare)
-
L2-convergence of Yosida approximation for semi-linear backward stochastic differential equation with jumps in infinite dimension
- 2024
-
Ingår i: Arab Journal of Mathematical Sciences. - : Emerald Group Publishing Limited. - 1319-5166 .- 2588-9214.
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: The main motivation of this paper is to present the Yosida approximation of a semi-linear backward stochastic differential equation in infinite dimension. Under suitable assumption and condition, an L2-convergence rate is established.Design/methodology/approach: The authors establish a result concerning the L2-convergence rate of the solution of backward stochastic differential equation with jumps with respect to the Yosida approximation.Findings: The authors carry out a convergence rate of Yosida approximation to the semi-linear backward stochastic differential equation in infinite dimension.Originality/value: In this paper, the authors present the Yosida approximation of a semi-linear backward stochastic differential equation in infinite dimension. Under suitable assumption and condition, an L2-convergence rate is established.
|
|
| 5. |
- Abidi, Hani, et al.
(författare)
-
Spatial convergence for semi-linear backward stochastic differential equations in Hilbert space : a mild approach
- 2020
-
Ingår i: Computational and Applied Mathematics. - : Springer. - 2238-3603 .- 1807-0302. ; 39:2, s. 1-11
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present convergence results of a spatial semi-discrete approximation of a Hilbert space-valued backward stochastic differential equations with noise driven by a cylindrical Q-Wiener process. Both the solution and its space discretization are formulated in mild forms. Under suitable assumptions of the final value and the drift, a convergence rate is established.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
- Andersson, Roger, et al.
(författare)
-
Large Housing Estates in Stockholm and Jönköping, Sweden : Opinions of residents on recent developments
- 2005
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- RESTATE is the acronyme for Restructuring Large-scale Housing Estates in European Cities: Good Practices and New Visions for Sustainable Neighbourhoods and Cities. All the participants in this project share the basic underlying conviction: if the problems of these large-scale housing estates are not resolved, they will increasingly hinder the good economic functioning of cities. The study draws on estates in ten European countries: France, Germany, Hungury, Italy, the Netherlands, Poland, Slovenia, Spain, Sweden and the United Kingdom. Most results in this report are based on a survey carried out in the estates. The opinions and experiences of the inhabitants of the estates stand to the fore in this survey. This report is concerned with two Swedish cities, Stockholm and Jönköping; the same kind of information for estates in other countries in the RESTATE project can be found in parallel reports.
|
|
| 13. |
|
|
| 14. |
- Andersson, Roger, et al.
(författare)
-
Large Housing Estates in Sweden. Overview of developments and problems in Jönköping and Stockholm
- 2003
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- All over Europe massive numbers of people live in large-scale housing estates built after the Second World War. The estates were carefully planned, but now often manifest a mulitude af problems. They house large numbers of low-income households, the unemployment rates are above average and in some countries they have become concentration areas for ethnic minorities. Many estates are becoming increasingly associated with crime and social exclusion. The circumstances on the estates and policy initiatives associated with these are focus of the RESTATE-project. RESTATE is the acronym for Restructuring Large-scale Housing Estates in European Cities: Good Practices and New Visions for Sustainable Neighbourhoods and Cities. The study draws on estates in ten European countries: France, Germany, Hungary, Italy, the Netherlands, Poland, Slovenia, Spain, Sweden and the United Kingdom. The present report deals specifically with large housing estates in two cities in Sweden: Jönköping och Stockholm. The basic questions are about physical structure, demographic-, economic- and socio-cultural developments. The same kind of information for estates in other countries in the RESTATE-project can be found in the parallel reports
|
|
| 15. |
- Arharas, Ihsan, et al.
(författare)
-
Epidemic modelling by birth-death processes with spatial scaling
- 2024
-
Ingår i: Journal of Mathematics in Industry. - : Springer. - 2190-5983. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- In epidemic modeling, interpretation of compartment quantities, such as s, i, and r in relevant equations, is not always straightforward. Ambiguities regarding whether these quantities represent numbers or fractions of individuals in each compartment rise questions about significance of the involved parameters. In this paper, we address these challenges by considering a density-dependent epidemic modelling by a birth-death process approach inspired by Kurtz from 1970s'. In contrast to existing literature, which employs population size scaling under constant population condition, we scale with respect to the area. Namely, under the assumption of spatial homogeneity of the population, we consider the quantities of susceptible, infective and recovered per unit area. This spatial scaling allows diffusion approximation for birth-death type epidemic models with varying population size. By adopting this approach, we anticipate to contribute to a clear and transparent description of compartment quantities and parameters in epidemic modeling.
|
|
| 16. |
- Bagni, Tommaso, et al.
(författare)
-
Modeling Results of the Quench Behavior of a Nb-Ti Canted-Cosine-Theta Corrector Magnet for LHC
- 2024
-
Ingår i: IEEE transactions on applied superconductivity (Print). - : Institute of Electrical and Electronics Engineers (IEEE). - 1051-8223 .- 1558-2515. ; 34:5, s. 1-5
-
Tidskriftsartikel (refereegranskat)abstract
- A newly designed superconducting magnet of the Canted-Cosine-Theta (CCT) type was developed as a result of a collaboration between Swedish universities (Uppsala and Linneaus) and Swedish industries. This magnet was designed to function as a replacement of the present LHC orbit corrector magnets, which are approaching their end of life due to the radiation load. As a result, the new CCT magnet was developed to be more radiation tolerant and to constitute a one-to-one replacement to the currently installed version, which is a 1 m long 70 mm double aperture dipole magnet. The final magnet, which is currently under construction, will be tested at FREIA laboratory at Uppsala University and generate a magnetic field of 3.3 T and an integrated field of 2.8 Tm at about 85 A. To examine the magnet quench behavior and to identify a suitable quench protection system, the 3D electro-magnetic and thermal behavior of the coil was modeled using the RAT-Raccoon software. Based on the simulation results, a Metrosil varistor was selected to protect the magnet during the test. In this article, we report the results of the numerical analysis. The magnet model is equipped with a spot heater to initialize the quench and the temperature and voltages are monitored during the avalanche effect. The simulated current decay and the hot-spot temperature are analyzed with a focus on the impact of quench-back on the magnet protection.
|
|
| 17. |
- Bahar, Bahram, et al.
(författare)
-
Developing A-GPS as a Student Project
- 2006
-
Rapport (populärvet., debatt m.m.)abstract
- The project consists of ten fourth-year computer science students at Uppsala University developing an A-GPS (Assisted-GPS) system. During the fall term of 2005 the students have developed a module for GPS-calculations in a GSM-network and an application that demonstrates a possible way of using the calculations module. This paper describes the design, the development process and the results of the project.
|
|
| 18. |
- Bargholtz, Chr., et al.
(författare)
-
Measurement of the eta -> pi(+)pi(-)e(+)e(-) decay branching ratio
- 2007
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 644:5-6, s. 299-303
-
Tidskriftsartikel (refereegranskat)abstract
- The reaction pd -> He-3 eta at threshold was used to provide a clean source of eta mesons for decay studies with the WASA detector at CELSIUS. The branching ratio of the decay eta -> pi(+)pi(-)e(+)e(-) is measured to be (4.3 +/- 1.3 +/- 0.4) x 10(-4).
|
|
| 19. |
- Bargholtz, Chr., et al.
(författare)
-
The WASA detector facility at CELSIUS
- 2008
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 594:3, s. 339-350
-
Tidskriftsartikel (refereegranskat)abstract
- The WASA 4 pi multidetector system, aimed at investigating light meson production in light ion collisions and eta meson rare decays at the CELSIUS storage ring in Uppsala is presented. A unique feature of the system is the use of hydrogen pellets as internal targets for the first time. A detailed description of the design, together with the anticipated and achieved performance parameters are given. (C) 2008 Elsevier B.V. All rights reserved.
|
|
| 20. |
- Bashkanov, M., et al.
(författare)
-
Double-Pionic Fusion of Nuclear Systems and the "ABC" Effect : Approaching a Puzzle by Exclusive and Kinematically Complete Measurements
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 052301-
-
Tidskriftsartikel (refereegranskat)abstract
- The ABC effect-a puzzling low-mass enhancement in the pi pi invariant mass spectrum, first observed by Abashian, Booth, and Crowe-is well known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on the first exclusive and kinematically complete measurements of the most basic double-pionic fusion reaction pn -> d pi(0)pi(0) at beam energies of 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a (pi pi)(I=L=0) channel phenomenon associated with both a resonancelike energy dependence in the integral cross section and the formation of a Delta Delta system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data.
|
|
| 21. |
- Bashkanov, M., et al.
(författare)
-
Measurement of the slope parameter for the η → 3π0 decay in the pp → ppη reaction
- 2007
-
Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 76:4, s. 048201-
-
Tidskriftsartikel (refereegranskat)abstract
- The CELSIUS-WASA setup is used to measure the 3π0 decay of η mesons produced in pp interactions with beam kinetic energies of 1.36 and 1.45 GeV. The efficiency-corrected Dalitz plot and density distributions for this decay are shown, together with a fit of the quadratic slope parameter α yielding α = −0.026 ± 0.010(stat) ± 0.010(syst). This value is compared to recent experimental results and theoretical predictions.
|
|
| 22. |
- Belgrano, Valerio, et al.
(författare)
-
Response and Toxicity of Repeated Isolated Limb Perfusion (re-ILP) for Patients With In-Transit Metastases of Malignant Melanoma.
- 2019
-
Ingår i: Annals of surgical oncology. - : Springer Science and Business Media LLC. - 1534-4681 .- 1068-9265. ; 26:4, s. 1055-1062
-
Tidskriftsartikel (refereegranskat)abstract
- Isolated limb perfusion (ILP) is a safe and well-established treatment for in-transit metastases of melanoma. In case of relapse or disease progression, ILP can be repeated (re-ILP). This study aimed retrospectively to analyze a large consecutive series of re-ILP and compare clinical outcomes with first-time ILP.Between 2001 and 2015, 290 consecutive patients underwent 380 ILPs. Of these, 90 were re-ILPs including 68second ILPs, 16 third ILPs, 4 fourth ILPs, and two fifth ILPs. The study evaluated response (using World Health Organization [WHO] criteria), local toxicity (using the Wieberdink scale), and complications (using Clavien-Dindo).The results were compared between the first ILP, the second ILP, and the third to fifth ILP. The overall response rate was respectively 83%, 80% and 68%, with a complete response (CR) rate of 60%, 41%, and 59%. In the re-ILP group, the patients with a CR after the first ILP had a 65% CR rate after the second ILP compared with 8% for the patients without a CR (p=0.001). The risk for local toxicity or complications was not increased after re-ILP. The median overall survival periods were respectively 34, 41, and 93months (p=0.02).As a therapeutic option, ILP can be repeated safely for in-transit metastases of melanoma, achieving similar high response rates without increasing complications or toxicity. Re-ILP is mainly indicated for patients who already had a CR after the first ILP, whereas other treatment options should be considered for primary non-responders.
|
|
| 23. |
- Berlowski, M., et al.
(författare)
-
Measurement of eta meson decays into lepton-antilepton pairs
- 2008
-
Ingår i: Physical Review D. Particles and fields. - : American Physical Society. - 0556-2821 .- 1089-4918. ; 77:3, s. 032004-
-
Tidskriftsartikel (refereegranskat)abstract
- A search for rare lepton decays of the eta meson was performed using the WASA detector at CELSIUS. Two candidates for double Dalitz decay eta -> e(+)e(-)e(+)e(-) events are reported with a background of 1.3 +/- 0.2 events. This allows to set an upper limit to the branching ratio of 9.7x10(-5) (90% CL). The branching ratio for the decay eta -> e(+)e(-)gamma is determined to (7.8 +/- 0.5(stat)+/- 0.8(syst))x10(-3) in agreement with world average value. An upper limit (90% CL) for the branching ratio for the eta -> e(+)e(-) decay is 2.7x10(-5) and a limit for the sum of the eta ->mu(+)mu(-)mu(+)mu(-) and eta ->pi(+)pi(-)mu(+)mu(-) decays is 3.6x10(-4).
|
|
| 24. |
- Berrhazi, Badr-eddine, et al.
(författare)
-
A stochastic SIRI epidemic model with Lévy noise
- 2018
-
Ingår i: Discrete and continuous dynamical systems. Series B. - : American Institute of Mathematical Sciences. - 1531-3492 .- 1553-524X. ; 23:6, s. 2415-2431
-
Tidskriftsartikel (refereegranskat)abstract
- Some diseases such as herpes, bovine and human tuberculosis exhibit relapse in which the recovered individuals do not acquit permanent immunity but return to infectious class. Such diseases are modeled by SIRI models. In this paper, we establish the existence of a unique global positive solution for a stochastic epidemic model with relapse and jumps. We also investigate the dynamic properties of the solution around both disease-free and endemic equilibria points of the deterministic model. Furthermore, we present some numerical results to support the theoretical work.
|
|
| 25. |
- Berrhazi, Badr-eddine, et al.
(författare)
-
A stochastic SIRS epidemic model incorporating media coverage and driven by Levy noise
- 2017
-
Ingår i: Chaos, Solitons & Fractals. - : Elsevier. - 0960-0779 .- 1873-2887. ; 105, s. 60-68
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we establish the existence of a unique global positive solution for a stochastic epidemic model, incorporating media coverage and driven by Levy noise. We also investigate the dynamic properties of the solution around both disease-free and endemic equilibria points of the deterministic model. Furthermore, we present some numerical results to support the theoretical work. (C) 2017 Elsevier Ltd. All rights reserved.
|
|
| 26. |
- Berrhazi, Badr-eddine, et al.
(författare)
-
A stochastic viral infection model driven by Levy noise
- 2018
-
Ingår i: Chaos, Solitons & Fractals. - : Elsevier. - 0960-0779 .- 1873-2887. ; 114, s. 446-452
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we are interested in the study of a stochastic viral infection model with immune impairment driven by Levy noise. First we prove the existence of a unique global solution to the model. By means of the Lyapunov method we study the stability of the equilibria. We present sufficient conditions for the extinction and persistence in mean. Furthermore, we present some numerical results to support the theoretical work.
|
|
| 27. |
- Berrhazi, Badr-Eddine, et al.
(författare)
-
Media effects on the dynamics of a stochastic SIRI epidemic model with relapse and Lévy noise perturbation
- 2019
-
Ingår i: International Journal of Biomathematics. - : World Scientific Publishing Co. Pte Ltd. - 1793-5245 .- 1793-7159. ; 12:3
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we study the dynamic properties of an SIRI epidemic model incorporating media coverage, and stochastically perturbed by a Lévy noise. We establish the existence of a unique global positive solution. We investigate the dynamic properties of the solution around both disease-free and endemic equilibria points of the deterministic model depending on the basic reproduction number under some noise excitation. Furthermore, we present some numerical simulations to support the theoretical results. © 2019 World Scientific Publishing Company.
|
|
| 28. |
- Berrhazi, Badr-eddine, et al.
(författare)
-
RBDSDEs with jumps and optional Barrier and mean field game with common noise
- 2023
-
Ingår i: Stochastics. - : Taylor & Francis Group. - 1744-2508 .- 1744-2516. ; 95:4, s. 615-634
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we study a generalization of reflected backward doubly stochastic differential equations (RBDSDEs) and present a link to a general mean field game. In our case, the RBDSDEs are associated with a lower optional not right continuous barrier. First, we establish the existence and uniqueness of a solution of such RBDSDEs. We then study a mean field game with a new type of common noise related to an electricity grid with storage allowing jumps and prove the existence of a mean field Nash equilibrium.
|
|
| 29. |
- Berrhazi, Badr-eddine, et al.
(författare)
-
Reflected backward doubly stochastic differential equations with discontinuous barrier
- 2020
-
Ingår i: Stochastics. - : Taylor & Francis Group. - 1744-2508 .- 1744-2516. ; 92:7, s. 1100-1124
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we investigate reflected backward doubly stochastic differential equations (RBDSDEs) with a lower not necessarily right-continuous obstacle. First, we establish the existence and uniqueness of a solution to RBDSDEs with Lipschitz drivers. In the second part, we present a comparison theorem and we prove the existence of a minimal solution to the RBDSDE with the continuous driver.
|
|
| 30. |
|
|
| 31. |
|
|
| 32. |
|
|
| 33. |
|
|
| 34. |
- Boman, Christoffer, et al.
(författare)
-
Stove performance and emission characteristics in residential wood log and pellet combustion : Part 1: Pellet stoves
- 2011
-
Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 25:1, s. 307-314
-
Tidskriftsartikel (refereegranskat)abstract
- Stove performance, characteristics and quantities of gaseous and particulate emissions were determined for two different pellet stoves, varying fuel load, pellet diameter and chimney draught. This approach aimed at covering variations in emissions from stoves in use today. The extensive measurement campaign included CO, NOx, organic gaseous carbon, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), total particulate matter (PMtot) as well as particle mass and number concentrations, size distributions and inorganic composition. At high load, most emissions were similar. For stove B, operating at high residual oxygen and solely with primary air, the emissions of PMtot and particle numbers were higher while the particles were smaller. Lowering the fuel load, the emissions of CO and hydrocarbons increased dramatically for stove A, which operated continuously also at lower fuel loads. On the other hand for stove B, which had intermittent operation at lower fuel loads, the emissions of hydrocarbons increased only slightly lowering the fuel load, while CO emissions increased sharply, due to high emissions at the end of the combustion cycle. Beside methane, dominating VOCs were ethene, acetylene and benzene and the emissions of VOC varied in the range 1.1-47 mg/MJfuel. PAH emissions (2-340 µg/MJfuel) were generally dominated by phenantrene, fluoranthene and pyrene. PMtot (15-45 mg/MJfuel) were in all cases dominated by fine particles with mass median diameters in the range 100-200 nm, peak mobility diameters of 50-85 nm and number concentrations in the range 4×1013- 3×1014 particles/MJfuel. During high load conditions the particulate matter was totally dominated by inorganic particles at 15-25 mg/MJfuel consisting of potassium, sodium, sulfur and chlorine, in the form of K2SO4, K3Na(SO4)2 and KCl. The study shows that differences in operation and modulation principles for the tested pellet stoves, relevant for appliances in use today, will affect the performance and emissions significantly, although with lower scattering in the present study compared to compiled literature data.
|
|
| 35. |
- Bouggar, Driss, et al.
(författare)
-
Stochastic near-optimal controls for treatment and vaccination in a COVID-19 model with transmission incorporating Lévy jumps
- 2024
-
Ingår i: Stochastics. - : Taylor & Francis Group. - 1744-2508 .- 1744-2516. ; 96:1, s. 887-920
-
Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 pandemic has triggered a groundbreaking reliance on mathematical modelling as an important tool for studying and managing the spread of the virus since its emergence. Public health preventive measures such as vaccination and therapeutics can effectively reduce or eradicate an infectious disease. This work investigates these two strategies for controlling the COVID-19 epidemic through a stochastic epidemiological modelling approach. The existence and uniqueness of a positive solution of the stochastic system is studied. A priori estimates of the vaccination and treatment controls are established. Sufficient and necessary conditions are obtained for the near-optimal control problem of the stochastic model using the maximum condition of the Hamiltonian function and the Ekeland principle. Finally, to support our theoretical results, numerical simulations for a combination of optimized vaccination and treatment strategies were presented to understand the challenges posed by COVID-19 in Brazil.
|
|
| 36. |
- Caraballo, Tomas, et al.
(författare)
-
A stochastic SIRI epidemic model with relapse and media coverage
- 2018
-
Ingår i: Discrete and continuous dynamical systems. Series B. - : American Institute of Mathematical Sciences. - 1531-3492 .- 1553-524X. ; 23:8, s. 3483-3501
-
Tidskriftsartikel (refereegranskat)abstract
- This work is devoted to investigate the existence and uniqueness of a global positive solution for a stochastic epidemic model with relapse and media coverage. We also study the dynamical properties of the solution around both disease-free and endemic equilibria points of the deterministic model. Furthermore, we show the existence of a stationary distribution. Numerical simulations are presented to confirm the theoretical results.
|
|
| 37. |
- Caraballo, Tomas, et al.
(författare)
-
Analysis of a stochastic distributed delay epidemic model with relapse and Gamma distribution kernel
- 2020
-
Ingår i: Chaos, Solitons & Fractals. - : Elsevier. - 0960-0779 .- 1873-2887. ; 133, s. 1-8
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, we investigate a stochastic epidemic model with relapse and distributed delay. First, we prove that our model possesses and unique global positive solution. Next, by means of the Lyapunov method, we determine some sufficient criteria for the extinction of the disease and its persistence. In addition, we establish the existence of a unique stationary distribution to our model. Finally, we provide some numerical simulations for the stochastic model to assist and show the applicability and efficiency of our results. (C) 2020 Elsevier Ltd. All rights reserved.
|
|
| 38. |
- El Attouga, Sanae, et al.
(författare)
-
Lévy noise with infinite activity and the impact on the dynamic of an SIRS epidemic model
- 2023
-
Ingår i: Physica A. - : Elsevier. - 0378-4371 .- 1873-2119. ; 618
-
Tidskriftsartikel (refereegranskat)abstract
- A stochastic SIRS epidemic model with generalized nonlinear incidence and Levy noise is investigated. First, we show the existence and uniqueness of a global positive solution. Then, we establish sufficient conditions for the extinction and persistence of the disease. The main results are proved under weak assumptions regarding the incidence function, the obtained results are proved under a Levy-type perturbation without requiring the finiteness of its activity. Finally, numerical simulations are realized to illustrate the main results.(c) 2023 Elsevier B.V. All rights reserved.
|
|
| 39. |
- El Fatini, Mohamed, et al.
(författare)
-
A stochastic analysis for a triple delayed SIQR epidemic model with vaccination and elimination strategies
- 2020
-
Ingår i: Journal of Applied Mathematics and Computing. - : Springer. - 1598-5865 .- 1865-2085. ; 64, s. 781-805
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, a delayed SIQR epidemic model with vaccination and elimination hybrid strategies is analysed under a white noise perturbation. We prove the existence and the uniqueness of a positive solution. Afterwards, we establish a stochastic threshold R-s in order to study the extinction and persistence in mean of the stochastic epidemic system. Then we investigate the existence of a stationary distribution for the delayed stochastic model. Finally, some numerical simulations are presented to support our theoretical results.
|
|
| 40. |
- El Fatini, Mohamed, et al.
(författare)
-
A stochastic threshold of a delayed epidemic model incorporating Lévy processes with harmonic mean and vaccination
- 2020
-
Ingår i: International Journal of Biomathematics. - : World Scientific. - 1793-5245 .- 1793-7159. ; 13:7
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this paper is to investigate a stochastic threshold for a delayed epidemic model driven by Levy noise with a nonlinear incidence and vaccination. Mainly, we derive a stochastic threshold R-s which depends on model parameters and stochastic coefficients for a better understanding of the dynamical spreading of the disease. First, we prove the well posedness of the model. Then, we study the extinction and the persistence of the disease according to the values of R-s. Furthermore, using different scenarios of Tuberculosis disease in Morocco, we perform some numerical simulations to support the analytical results.
|
|
| 41. |
- El Fatini, Mohamed, et al.
(författare)
-
Bayesian forecast of the basic reproduction number during the Covid-19 epidemic in Morocco and Italy
- 2021
-
Ingår i: Mathematical Population Studies. - : Taylor & Francis Group. - 0889-8480 .- 1547-724X. ; 28:4, s. 228-242
-
Tidskriftsartikel (refereegranskat)abstract
- In a Covid-19 susceptible-infected-recovered-dead model with time-varying rates of transmission, recovery, and death, the parameters are constant in small time intervals. A posteriori parameters result from the Euler-Maruyama approximation for stochastic differential equations and from Bayes' theorem. Parameter estimates and 10-day predictions are performed based on Moroccan and Italian Covid-19 data. Mean absolute errors and mean square errors indicate that predictions are of good quality.
|
|
| 42. |
- El Fatini, Mohamed, et al.
(författare)
-
Epidemic modeling : Diffusion approximation vs. stochastic differential equations allowing reflection
- 2021
-
Ingår i: International Journal of Biomathematics. - : World Scientific. - 1793-5245 .- 1793-7159. ; 14:5
-
Tidskriftsartikel (refereegranskat)abstract
- A birth-death process is considered as an epidemic model with recovery and transmittance from outside. The fraction of infected individuals is for huge population sizes approximated by a solution of an ordinary differential equation taking values in [0, 1]. For intermediate size or semilarge populations, the fraction of infected individuals is approximated by a diffusion formulated as a stochastic differential equation. That diffusion approximation however needs to be killed at the boundary {0}boolean OR{1}. An alternative stochastic differential equation model is investigated which instead allows a more natural reflection at the boundary.
|
|
| 43. |
- El Fatini, Mohamed, et al.
(författare)
-
Levy noise perturbation for an epidemic model with impact of media coverage
- 2019
-
Ingår i: Stochastics. - : Taylor & Francis. - 1744-2508 .- 1744-2516. ; 91:7, s. 998-1019
-
Tidskriftsartikel (refereegranskat)abstract
- This work is devoted to study the existence and uniqueness of global positive solution for a stochastic epidemic model with media coverage driven by Levy noise. We also investigate the dynamic properties of the solution around both disease-free and endemic equilibria points of the deterministic model. Numerical simulations are presented to confirm the theoretical results.
|
|
| 44. |
- El Fatini, Mohamed, et al.
(författare)
-
Stochastic stability and instability of an epidemic model with relapse
- 2018
-
Ingår i: Applied Mathematics and Computation. - : Elsevier. - 0096-3003 .- 1873-5649. ; 316, s. 326-341
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a stochastic epidemic model with relapse. First, we prove global positivity of solutions. Then we discuss stability of the disease-free equilibrium state and we show extinction of epidemics using Lyapunov functions. Furthermore we show persistence of the disease under some conditions on parameters of the model. Our numerical simulations confirm the analytical results. (C) 2017 Elsevier Inc. All rights reserved.
|
|
| 45. |
- El Fatini, Mohamed, et al.
(författare)
-
The effect of stochasticity with respect to reinfection and nonlinear transition states for some diseases with relapse
- 2020
-
Ingår i: Mathematical methods in the applied sciences. - : John Wiley & Sons. - 0170-4214 .- 1099-1476. ; 43:18, s. 10659-10670
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we consider a stochastic epidemic model with relapse, reinfection, and a general incidence function. Using stochastic tools, we establish a stochastic thresholdRs0and prove the extinction of the disease when its value is equal or less than unity. We also show the persistence in mean of the disease whenRs0>1.Moreover, we prove the existence and uniqueness of a stationary distribution. Finally, numerical simulations are presented to show the effectiveness of theoretical results.
|
|
| 46. |
- Eriksson, Axel, et al.
(författare)
-
Particulate PAH Emissions from Residential Biomass Combustion : Time-Resolved Analysis with Aerosol Mass Spectrometry
- 2014
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:12, s. 7143-7150
-
Tidskriftsartikel (refereegranskat)abstract
- Time-resolved emissions of particulate polycyclic aromatic hydrocarbons (PAHs) and total organic particulate matter (OA) from a wood log stove and an adjusted pellet stove were investigated with high-resolution time-of-flight aerosol mass spectrometry (AMS). The highest OA emissions were found during the addition of log wood on glowing embers, that is, slow burning pyrolysis conditions. These emissions contained about 1% PAHs (of OA). The highest PAH emissions were found during fast burning under hot air starved combustion conditions, in both stoves. In the latter case, PAHs contributed up to 40% of OA, likely due to thermal degradation of other condensable species. The distribution of PAHs was also shifted toward larger molecules in these emissions. AMS signals attributed to PAHs were found at molecular weights up to 600 Da. The vacuum aerodynamic size distribution was found to be bimodal with a smaller mode (Dva ~ 200 nm) dominating under hot air starved combustion and a larger sized mode dominating under slow burning pyrolysis (Dva ~ 600 nm). Simultaneous reduction of PAHs, OA and total particulate matter from residential biomass combustion may prove to be a challenge for environmental legislation efforts as these classes of emissions are elevated at different combustion conditions.
|
|
| 47. |
|
|
| 48. |
- Faymonville, Louise, 1979-
(författare)
-
Hövisk litteratur och förändringar i det fornsvenska textlandskapet
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aims to shed light on the presence of the Old Swedish courtly literature in the changing profane textual landscape of medieval Sweden to better understand the function and significance of this literature. The point of departure for this study are the three verse romances collectively known as the Eufemiavisor and their properties in their capacity as courtly literature. The material consists of 31 profane literary works and 26 manuscripts produced between 1300 and 1529. The study draws on polysystem theory (Even-Zohar 1990) and makes use of notions and approaches from various fields of textual scholarship such as philology and the history of literature.The study is divided into three main parts. The first part focuses on the work perspective and structures the development of the Old Swedish profane textual landscape into four stages: introduction and establishment; diversification and expansion; politicizing and centralisation; and further development and administration of literary traditions. The second part, which analyses the use of a courtly repertoire in the corpus, uses these stages to interpret the results. The courtly repertoire is defined as a set of properties manifested in the Eufemiavisor. The properties included in the analysis are a courtly vocabulary, certain expressions, the form Knittelvers, adventure as a theme, and the intratextual temporal and spatial settings. The analysis shows that certain parts of the repertoire quickly become obsolete while others (such as a core vocabulary and the Knittelvers) remain productive until the end of the Middle Ages but gradually transform into stereotypes or evolve to become useful outside of a courtly literary context. The third part focuses on the manuscript perspective. A network analysis of the texts’ appearances in manuscripts shows that even though the Eufemiavisor had a central position, the rhyme chronicle Erikskrönikan could be considered the central node connecting various interests and textual orientations, keeping the chronicle relevant throughout the Middle Ages. The analysis of the transmission of the Eufemiavisor reveals their dynamic and multifunctional nature. Of the three romances, Hertig Fredrik av Normandie is perhaps the most nuanced, a factor that may have contributed to it being the most copied as well as the longest-lasting of the Eufemiavisor.The results suggest a gradual move of the courtly repertoire from a central position towards a peripheral position in the literary system as a consequence of a growing system, new interests, and new groups governing the system. By the end of the Middle Ages, the function of the courtly repertoire appears to have become one of preservation of traditional literary taste.
|
|
| 49. |
- Fredriksson, Emelie, et al.
(författare)
-
Wildfire yields a distinct turnover of the beetle community in a semi-natural pine forest in northern Sweden
- 2020
-
Ingår i: Ecological processes. - : Springer Science and Business Media LLC. - 2192-1709. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Background Fires have been an important natural disturbance and pervasive evolutionary force in the boreal biome. Yet, fire suppression has made forest fires rare in the managed landscapes in Fennoscandia, causing significant habitat loss for saproxylic species such as polypores and insects. To better understand how the beetle community changes (species turnover) after a wildfire in a landscape with intense fire suppression, we monitored beetles with flight intercept traps the first 3 years as well as 12 years after a large wildfire in a national park in northern Sweden (a control/unburnt area was set up for the last year of sampling). Results Species composition changed significantly among all studied years with a continuous turnover of species following the wildfire. The indicator species analysis showed that year 1 post-fire was mostly associated with cambium consumers and also the pyrophilous speciesBatrisodes hubenthali. Year 2 was the most abundant and species-rich year, withTomicus piniperdaas the most important indicator species. The indicator species year 3 were mostly secondary successional species, fungivores, and predators and were characterized by lower species diversity. Year 12 had higher diversity compared with year 3 but lower species richness and abundance. A control area was established during year 12 post-fire, and our analyses showed that the control area and burned area differed in species composition suggesting that the beetle community needs longer than 12 years to recover even after a low-intensive ground fire. Conclusion The wildfire area hosted several red-listed and fire-dependent species suggesting that after a century of landscape-level fire suppression in a semi-natural area, the reintroduction of fire benefits rare and pyrophilous species and still impacts species composition after 12 years. This study implies that fire has long-lasting effects on high latitudes and that prescribed burning has the potential to benefit biodiversity over decades in these landscapes while also highlighting the value of considering the whole species community and not only monitoring abundance and richness to assess biodiversity after management actions.
|
|
| 50. |
- Haas, Rüdiger, 1966, et al.
(författare)
-
Status of the Onsala Twin Telescopes – One Year After the Inauguration
- 2019
-
Ingår i: IVS 2018 General Meeting Proceedings "Global Geodesy and the Role of VGOS – Fundamental to Sustainable Development". ; NASA/CP-2019-219039, s. 17-19
-
Konferensbidrag (refereegranskat)abstract
- We briefly describe the status of the Onsala twin telescopes and the experience gained since the official inauguration in May 2017.
|
|
