Las hormigas invasoras desplazan a las especies de hormigas nativas y otros artrópodos. Como consecuencia, las interacciones biológicas del sistema invadido y los servicios ecológicos prestados por las especies nativas son modificados. El objetivo de este trabajo fue investigar los efectos de la hormiga invasora Lasius neglectus sobre algunos de los componentes superficiales y subsuperficiales de un encinar urbano y compararlos con los efectos de las hormigas nativas, en particular con Lasius grandis. Lasius neglectus visita principalmente árboles aislados donde permanece más meses atendiendo áfidos. Por el contrario, las hormigas nativas no visitaron los árboles según su ubicación (aislado, borde o centro del bosque). Excepto en el caso de la hormiga nativa Lasius grandis, que permaneció más tiempo en los árboles aislados cuando Lasius neglectus no estaba presente en el fragmento. La riqueza de especies nativas de hormigas y su visita a los árboles fue menor en fragmentos de bosque con Lasius neglectus. Crematogaster scutellaris, Temnothorax lichtensteini y Lasius grandis lograron coexistir con la hormiga invasora. La estructura de la comunidad de hormigas nativas en fragmentos con o sin Lasius neglectus mostró un patrón aleatorio. Entre Mayo y Octubre, en las encinas se encontraron dos especies de áfidos, Hoplocallis picta, ocasionalmente atendido por las hormigas, y Lachnus roborisun un mirmecófilo obligado. En encinas visitadas por la hormiga invasora, se observó que la abundancia de Lachnus roboris tendió a duplicarse, como así también su producción de melaza, porcentaje de colonias atendidas comparado con los resultados obtenidos en encinas visitadas por la hormiga nativa Lasius grandis. Consecuentemente, durante el periodo estudiado la hormiga invasora duplicó su colecta de melaza por encina respecto de la hormiga nativa. Las colonias de Lachnus roboris se ubicaron principalmente sobre las bellotas. Sin embargo, no se detectó ningún efecto en la producción o calidad de bellotas y en la emergencia o calidad de las plántulas. Ambas especies de hormigas capturaron principalmente Pscópteros y Hoplocallis picta como fuente de proteínas. El porcentaje de obreras que llevaba insectos o trozos de artrópodos entre sus mandíbulas fue superior para Lasius grandis. La comunidad de artrópodos y el nivel de herbivoría no fueron modificados por la presencia de una u otra especie de hormiga. Sin embargo, en las encinas visitadas por Lasius neglectus las arañas, los curculiónidos y los áfidos tendieron a incrementar su abundancia mientras que las larvas de coccinélidos (predadores de áfidos) disminuyeron marcadamente. La melaza que no es recogida por las hormigas puede incorporarse al suelo disuelta en el agua de trascolación de la copa como carbono orgánico disuelto (COD). La colecta de melaza de Lasius neglectus disminuyó el COD disuelto en el agua de trascolación de las encinas lo cual indicaría una interrupción del flujo de materia y energía entre la copa de las encinas y el suelo aledaño. En relación a los efectos subsuperficiales se observó que el contenido de nutrientes en el suelo aledaño a las encinas visitas por Lasius neglectus fue mayor respecto del encontrado en encinas visitadas por hormigas nativas. Asimismo, la comunidad de microorganismos se diferenció según la presencia de hormigas nativas o de la invasora; tendiendo la biomasa microbiana del suelo a ser mayor en el caso de la presencia de Lasius neglectus. Según la localidad estudiada, la calidad de la hojarasca producida fue menor en los árboles visitados por Lasius neglectus. Sin embargo, la descomposición de la hojarasca de encina no fue modificada por la presencia de la hormiga invasora. Se concluye que la presencia de Lasius neglectus modifica aquellos componentes, superficiales y subsuperficiales, del sistema de la encina que están directa o indirectamente relacionados con la colecta de melaza. / Invasive ants displace native ant species and other arthropods. As a consequence, at the invaded system biological interactions and ecological services provided by native ant species are modified. The aim of this study was to investigate some of the above-belowground effects of the invasive ant Lasius neglectus in an urban holm oak forest and to compare these effects with those of native ant species, in particular related to Lasius grandis.Lasius neglectus mainly visited isolated trees where workers remained more months tending aphids and other insects. On the contrary, native ant tree visitation was not related to tree position in the fragments (isolated, edges or core trees). The only exception was the native ant Lasius grandis which remained more months at isolated trees in fragments where Lasius neglectus was not present. Native ant species richness and its tree visitation were lower at fragments where Lasius neglectus was present. Crematogaster scutellaris, Temnothorax lichtensteini y Lasius grandis were able to coexist with the invasive ant specie. Community structure of native ants did not differ from a random pattern with or without Lasius neglectus.Some effects of the ant presence were investigated in detail at the holm oak (Quercus ilex) since this tree was the most abundant at the studied forest fragments. Between May and October, two aphid species were found feeding at holm oak canopy: Hoplocallis picta, which was occasionally tended and Lachnus roboris which was the main tended species. At holm oaks visited by the invasive ant, the abundance of Lachnus roboris tended to increase twice, as well as their honeydew production related to results obtained at holm oaks visited by the native ant Lasius grandis. The percentage of tended colonies tended by Lasius neglectus was higher compared to the percentage tended by Lasius grandis. As a consequence, at the studied period, the invasive ant collected two fold of honeydew per tree related to the native ant. At holm oaks visited by Lasius neglectus or Lasius grandis colonies of Lachnus roboris fed mainly on acorn petiole or on their cap. However, there was not any difference of acorn production acorn or quality and sapling emergency or quality between these holm oaks.Both ant species mainly captured Pscoptera and Hoplocallis picta as source of proteins. The percentage of workers carrying insects or pieces of arthropods in its jaws was higher for Lasius grandis. Arthropod community and herbivory level was not modified due the presence of the invasive or the native ant. However, some particular groups showed differences of its abundance. At holm oaks visited by Lasius neglectus, spiders, weevils and aphids tended to increase its abundance while ladybird larvae (aphid predators) decreased markedly.Honeydew production that was not collected by ants may reach the soil dissolved in throughfall as dissolved organic carbon (DOC). Honeydew collection by Lasius neglectus decreased DOC content in throughfall. This result suggests that the invasive ant interrupts the flux of energy and matter between canopy and the soil surrounding holm oaks.In relation with belowground effects of Lasius neglectus soil nutrient content was higher beneath holm oaks visited by the invasive ant in relation to those trees visited by native ants. Soil microbial community was characterized by the presence of Lasius neglectus and microbial biomass tended to increase beneath holm oaks visited by this invasive ant. Depending on the study site, litter quality was lower at holm oaks visited by Lasius neglectus. Litter decomposition was not modified by the presence of the invasive ant.I conclude that Lasius neglectus presence modifies those below-aboveground components of the holm oak system that are directly or indirectly related to honeydew collection.

Examensarbete.

The aim of the study was to examine how two young female victims was represented in Swedish commercial news press, if and how their relations to the perpetrator would affect their representation and what similarities and differences there were in the representation between the two. We examined the coverage of Lisa Holm, who was murdered by a stranger, and Tova Moberg, who was murdered by her abusing ex- boyfriend. The method used was a critical discourse analysis. We searched for different discourse themes in a total of twelve news articles from Aftonbladet and Expressen. We analyzed the themes and came to the conclusion that the murder victims were represented very much alike, well-liked, ambitious and good-hearted. The main difference is that Tova Moberg was not represented as innocent as Lisa Holm by the journalism because of her relationship with her ex-boyfriend. The journalism partly blamed Tova Moberg for not preventing her own death since she was aware of the danger. We found that as soon as any kind of relations between the victim and perpetrator was mentioned the victim’s status as an ideal victim decreased.

Dans cette thèse nous étudierons plusieurs problèmes de la théorie du contrôle portant sur des modèles non-linéaires issus de la mécanique des fluides. Dans le chapitre un, nous étudions l'équation de Camassa-Holm sur un intervalle compact de R. Après avoir introduit de bonnes conditions aux bords et une notion de solution faible, nous montrons un théorème d'existence et un théorème d'unicité fort-faible pour le problème mixte. Dans une seconde partie nous fournissons une loi de retour pour les données aux bords qui nous permet de stabiliser asymptotiquement l'état stationnaire naturel de l'équation.\par Dans le chapitre deux, nous étudions le problème de la contrôlabilité exacte d'une loi de conservation scalaire à flux convexe, posée sur un intervalle compact et dans le cadre des solutions entropiques. On fournit des conditions suffisantes sur des fonctions de BV pour qu'elles soient atteignables en temps arbitraire depuis n'importe quelle donnée initiale. On contrôle l'équation via les données aux bords et aussi grâce à un terme source agissant uniformément en espace.\par Enfin le chapitre trois est consacré au problème de la stabilisation asymptotique des états stationnaires constants d'une loi de conservation scalaire à flux convexe, posée sur un intervalle compact et dans le cadre des solutions entropiques. On contrôle à nouveau l'équation via les données aux bords et un terme source agissant uniformément en espace. Nous fournissons deux lois de retour stationnaires (suivant que l'état à stabiliser est de vitesse critique ou non) qui nous permettent de montrer la stabilisation asymptotique globale.

Denna studie syftar till att undersöka den lokala dimensionen av kriminaljournalistik genom att jämföra gestaltningen av brott, brottsoffer och förövare mellan nationell press och lokalpress. Undersökningen omfattar rapporteringen kring fallet Lisa Holm och fallet Arbogakvinnan och bygger på en kvalitativ innehållsanalys av totalt 126 webbartiklar från Expressen , Aftonbladet , Skaraborgs Allehanda och Bärgslagsbladet/Arboga tidning . Utgångspunkten för studien är gestaltningsteorin som bland annat har definierats av medieforskaren Adam Shehata. Uppsatsen innefattar en tolkande analys av gestaltningen av brott, brottsoffer och förövare i kvällspress respektive lokalpress. Studien visar att lokaltidningar rapporterar betydligt mindre om brott och olyckor än vad kvällstidningar gör, vilket är tvärt emot tidigare forskning. Studien visar även att lokala anknytningar sällan förekommer i lokalpressen men får stort fokus i kvällspressen. Studien visar även att kvällspressen fokuserar mer på närhet, och tar läsaren närmare händelsernas centrum, till skillnad från lokalpressen.

No description available.

In this thesis we employ two recent analytical approaches to investigate the possible classes of traveling wave solutions of some members of recently derived integrable family of generalized Camassa-Holm (GCH) equations. In the first part, a novel application of phase-plane analysis is employed to analyze the singular traveling wave equations of four GCH equations, i.e. the possible non-smooth peakon, cuspon and compacton solutions. Two of the GCH equations do no support singular traveling waves. We generalize an existing theorem to establish the existence of peakon solutions of the third GCH equation. This equation is found to also support four segmented, non-smooth M-wave solutions. While the fourth supports both solitary (peakon) and periodic (cuspon) cusp waves in different parameter regimes. In the second part of the thesis, smooth traveling waves of the four GCH equations are considered. Here, we use a recent technique to derive convergent multi-infinite series solutions for the homoclinic and heteroclinic orbits of their traveling-wave equations, corresponding to pulse and front (kink or shock) solutions respectively of the original PDEs. Unlike the majority of unaccelerated convergent series, high accuracy is attained with relatively few terms. Of course, the convergence rate is not comparable to typical asymptotic series. However, asymptotic solutions for global behavior along a full homoclinic/heteroclinic orbit are currently not available.

The aim of the study is to examine how the evening newspaper Aftonbladet portrays the murder victim Lisa Holm and her killer Nerijus Bilevicius, and how these portrayals are related to Nils Christie's theory about the ideal victim. The central questions investigated are: How are the victim and the perpetrator portrayed by the evening newspaper Aftonbladet, and how does Aftonbladet's portrayal relate to the theory of the ideal victim? To examine the research questions, a deductive thematic analysis was conducted. Before commencing the analysis, five themes were found based on Christie's theoretical framework, which served as the foundation for the analysis. The selection analyzed consisted of 48 chosen articles all written by Aftonbladet. The result of the analysis shows how Lisa is portrayed as "the girl" - a young and vulnerable individual, described as happy, shy, and goal-oriented. At the time of the crime, she was engaged in a respectable project, she had finished her work shift, and was on her way home. It is emphasized that the location of the crime, her workplace, cannot be blamed. The analysis also indicates that Lisa and Nerijus Bilevicius had no prior relationship, signifying that the perpetrator was unknown to the victim.  Nerijus, the perpetrator, is portrayed as large and malevolent, aligning with the idealized image of an offender. Despite a few positive descriptions from relatives, the negative descriptions prevail. The analysis of Aftonbladet's portrayal of Lisa Holm and Nerijus Bilevicius demonstrates a close alignment with Christie's model of the ideal victim and the ideal offender, fulfilling all five criteria outlined by Christie. These findings underscore how Aftonbladet's representation of Lisa and Nerijus resonates with the idealized image of a victim and perpetrator according to Christie's theory, emphasizing the media's impact on the public perception of crime victims and offenders. This case serves as an illustration, according to the perfect ideal victim. The results suggest that Aftonbladet portrays Lisa as the ideal victim and Nerijus as the ideal offender according to Christie's model. It emphasizes how media portrayal can influence our general perception of crime victims and offenders.

No description available.

Le sujet de cette thèse est la formation de singularités pour certaines équations d'évolution dispersives et/ou dissipatives non-linéaires. Notre travail est axé sur les problèmes de Cauchy, généralement avec des conditions aux limites périodiques ou dans tout $\mathbb{R}^n$. Notre objectif est de fournir les conditions nécessaires ou suffisantes (ou les deux) sur les données initiales $u_0(x)$, garantissant que la durée de vie $T^{*}$ de la solution résultant de $u_0$ est finie ou non. Nous étudions deux types d'équations : une équation parabolique non linéaires et une classe d'équations d'ondes dispersives. La première équation étudiée est un modèle $1D$ de propagation d’ondes non-linéaires, qui apparaît par exemple dans l'étude des vagues dans un canal ou des déformations d’une barre hyper-élastique. L'une des contributions décisives de notre travail sera celle-ci : la seule solution forte globale périodique du problème de Cauchy de la barre hyper-élastique qui s’annule en au moins un point est la solution identiquement nulle. Nous établissons également l'analogue de ce résultat dans le cas des solutions non-périodiques définies sur toute la droite réelle, avec limite nulle à l'infini. Notre analyse repose sur l'application de nouveaux critères d'explosion "locaux en espace” (local-in-space blowup criteria). Une deuxième équation étudiée est une généralisation de l'équation de la barre hyperélastique qui a été proposée par H. Holden et X. Raynaud. Cette généralisation peut couvrir de nombreux autres types d'équations avec des propriétés mathématiques intéressantes. Nous établirons alors des critères d'explosion locaux en espace pour les solutions de ce modèle. Plus précisément, il s'agira de critères qui ne font intervenir que les propriétés de la condition initiale $u_0$ au voisinage d'un seul point. Ils simplifient et étendent de précédents critères d'explosion pour cette équation. Ensuite, nous nous sommes intéressés à une famille d'équations connue dans la littérature sous le nom $b$-family equations. L'un des cas les plus notables de cette famille d'équations est l'équation de Degasperis-Procesi. Pour cette famille, nous avons obtenu des résultats similaires à ceux décris précédemment. Enfin, dans la dernière partie, il s'agit d'étudier le caractère bien posé, local ou global en temps, dans des espaces fonctionnels issus de l'analyse harmonique et ayant les bonnes propriétés d'invariance par rapport aux changements d'échelle. Nous étudions le problème de Cauchy non linéaire de l'équation de la chaleur. Après avoir établi une extension du résultat d'Y. Meyer sur l’existence de solutions globales à données petites dans les espaces de Besov homogènes $\dot{B}_{p}^{-\sigma, \infty}(\mathbb{R}^{3})$, où $3 < p < 9$ et $\sigma=1-3/p$, nous prouvons que les données initiales $u_0\in \mathcal{S}(\mathbb{R}^{3})$, arbitrairement petites dans ${\dot B^{-2/3,\infty}_{9}}(\mathbb{R}^{3})$, peuvent produire des solutions qui explosent en temps fini. En outre, cette explosion peut se produire après un temps arbitrairement court / The subject of this thesis is the formation of singularities for some nonlinear evolution equations of dissipative and/or dispersive type. Our work is focused on the Cauchy problems, usually with periodic boundary conditions or on the whole $\mathbb{R}^{n}$. Our aim is to provide the necessary or sufficient conditions (or both) on the initial data $u_0 (x)$, ensuring that the lifetime $T^{*}$ of the solution resulting from $u_0$ is finite or not. We study two types of equations: a nonlinear parabolic equation and a class of dispersive wave equations. In the first case, we study a one-dimensional model which describe the propagation of nonlinear waves in a channel or the deformations of a hyper-elastic rod. One decisive contibutions of our work will be this: the only global strong periodic solution of the rod equation vanishing in at least one point is the identically zero solution. We also establish the analogue of this result in the case of non-periodic solutions defined on the whole real line which vanish at infinity. Our analysis is based on the application of new local-in-space blowup criteria. The second equation that we consider is a generalization of the rod equation which was proposed by H. Holden and X. Raynaud. This generalization covers many other equations with interesting mathematical properties. We will establish criteria for the blowup in finite time that involve only the properties of the data $u_0$ in a neighborhood of a single point, thus simplifying and extending earlier blowup criteria for this equation. After, we study family of equations known in the literature as the $b$-family equations. One of the most notable cases of this family of equations is the Degasperis-Procesi equation. For this family we obtain similar results as those described above. Finally, the last part, we study the well-posedness, locally or globally in time of the nonlinear heat equation, in functional spaces having appropriate invariance properties relative to scale changes. After extending Y. Meyer's result establishing the existence of global solutions, under a smallness condition of the initial data in the homogeneous Besov spaces $\dot{B}_{p}^{-\sigma, \infty}(\mathbb{R}^{3})$, where $3 < p < 9$ and $\sigma=1-3/p$, we prove that initial data $u_0\in \mathcal{S}(\mathbb{R}^{3})$, arbitrarily small in ${\dot B^{-2/3,\infty}_{9}}(\mathbb{R}^{3})$, can produce solutions that explode in finite time. In addition, the blowup may occur after an arbitrarily short time.