I develop social evolution theory to study the evolution of cooperation as follows: (1) Many organisms undergo a dispersal phase prior to breeding; I demonstrate that knowing ones dispersal status aids the evolution of helping (by non-dispersers) and harming (by dispersers). (2) Policing driven by group-benefits may be selected to enforce cooperation in human and animal societies. I extend existing theory to show that policing may be harder to evolve that previously thought, but that it is maintained more readily than it evolves. (3) Archeological and anthropological evidence suggests that warfare was prevalent during our evolution. I show that, contrary to previous suggestions, between-group competition can favour any social behaviour (pro-social or anti-social) so long as it helps the group compete, and that such traits can be altruistic or mutually beneficial. (4) Reproductive leveling is analogous to policing; in the human literature there is doubt as to whether it can evolve. I extend my previous work to consider the coevolution of culturally and genetically inherited traits for reproductive leveling and selfishness. I find that cooperation can evolve between non-kin if they share the same culture. (5) Monogamy is thought to favour the evolution of cooperative breeding. I show that in the simplest case, because of the cost of competition between non-dispersing siblings, the level of promiscuity has little or no effect on the evolution of cooperation. (6) Spatial structure (limited dispersal) is thought to favour the evolution of inter-specific mutualisms as it aligns the partners’ interests. I consider the case of plant-fungi mutualisms and show that spatial structure can disfavour cooperation if it limits the potential fungal partners available to the plant.

Novel infectious diseases in humans are of great concern to public health authorities and researchers in epidemiology. Zoonotic pathogens in particular have the potential to cause epidemics without any or little warning. In this thesis, I investigate evolutionary and environmental conditions, and the interactions between both, which facilitate the zoonotic emergence of novel pathogens. I start with a list of the mechanisms and processes which might influence a zoonotic emergence, and identify some unsolved problems. I address these with multiple, theoretical models. First, I use a village-city model with different adaptation scenarios to examine the influence of spatial heterogeneity on the emergence process. I derive general analytical results for the statistical properties of emergence events, including the probability distribution of outbreak sizes. My results suggest that, for typical connection strengths between communities, spatial heterogeneity has only a weak effect on outbreak size distributions, and on the risk of emergence per introduction. Next, I extend the research on environmental conditions by looking at pathogen specialisation in multi-host systems. I derive threshold connectivities for which generalist pathogens, which infect multiple species and might therefore be more dangerous to cross into the human species, can sustain transmission and are not dominated by specialists, which can only cause sustained transmission chains in a single host species, but are able to cause emergences with little warning. My third research chapter is interested in the effect of the loss of biodiversity. I analytically derive expected prevalences for fast growing and slow growing species. If fast growing species tend to perform better in degraded environments, my analytical results suggest that the overall prevalence level of infectious diseases will rise as environments degrade, which facilitates the chance of zoonotic jumps. In my last research chapter, I examine the actual impact of a novel, emerging infectious disease. I use data from the recent `Swine flu' epidemic in England to estimate epidemiological parameters of the infectious agent. My results suggest that the majority of infected cases showed no or only mild symptoms. This reveals that more data than just the estimated number of cases are necessary to fully evaluate the danger of a possible zoonotic, emerging infectious disease. I conclude by discussing my results and the implications which these might have.

Cerebrospinal fluid (CSF) fills a system of cavities at the centre of the brain, known as ventricles, and the subarachnoid space surrounding the brain and the spinal cord. In addition, CSF is in free communication with the interstitial fluid of the brain tissue. Disturbances in CSF dynamics can lead to diseases that cause severe brain damage or even death. So-called infusion tests are frequently performed in the diagnosis of such diseases. In this type of test, changes in average CSF pressure are related to changes in CSF volume through infusion of known volumes of additional fluid. Traditionally, infusion tests are analysed with single compartment models, which treat all CSF as part of one compartment and balance fluid inflow, outflow and storage through a single ordinary differential equation. Poroelastic models of the brain, on the other hand, have been used to simulate spatial changes with disease, particularly of the ventricle size, on larger time scales of days, weeks or months. Wirth and Sobey (2008) developed a two-fluid poroelastic model of the brain in which CSF pressure pulsations are linked to arterial blood pressure pulsations. In this thesis, this model is developed further and simulation results are compared to clinical data. At first, the functional form of the compliance, which governs the storage of CSF in single compartment models, is examined by comparison of two different compliance models with clinical data. The derivations of a single-fluid and a two-fluid poroelastic model of the brain in spherical symmetry are laid out in detail and some of the parameters are related to the compliance functions considered earlier. The finite element implementation of the two-fluid model is described and finally simulation results of the average CSF pressure response and the pressure pulsations are compared to clinical data.

Multiscale mathematical modelling is one of the major driving forces behind the systems biology revolution. The inherently interdisciplinary nature of its study and the multiple spatial and temporal scales which characterise its dynamics make cell migration an ideal candidate for a systems biology approach. Due to its ease of analysis and its compatibility with the type of data available, phenomenological continuum modelling has long been the default framework adopted by the cell migration modelling community. However, in recent years, with increased computational power, complex, discrete, cell-level models, able to capture the detailed dynamics of experimental systems, have become more prevalent. These two modelling paradigms have complementary advantages and disadvantages. The challenge now is to combine these two seemingly disparate modelling regimes in order to exploit the benefits offered by each in a comprehensive, multiscale equivalence framework for modelling cell migration. The main aim of this thesis is to begin with an on-lattice, individual-based model and derive a continuum, population-based model which is equivalent to it in certain limits. For simple models this is relatively easy to achieve: beginning with a one-dimensional, discrete model of cell migration on a regular lattice we derive a partial differential equation for the evolution of cell density on the same domain. We are also able to simply incorporate various signal sensing dynamics into our fledgling equivalence framework. However, as we begin to incorporate more complex model attributes such as cell proliferation/death, signalling dynamics and domain growth we find that deriving an equivalent continuum model requires some innovative mathematics. The same is true when considering a non-uniform domain discretisation in the one-dimensional model and when determining appropriate domain discretisations in higher dimensions. Higher-dimensional simulations of individual-based models bring with them their own computational challenges. Increased lattice sites in order to maintain spatial resolution and increased cell numbers in order to maintain consistent densities lead to dramatic reductions in simulation speeds. We consider a variety of methods to increase the efficiency of our simulations and derive novel acceleration techniques which can be applied to general reaction systems but are especially useful for our spatially extended cell migration algorithms. The incorporation of domain growth in higher dimensions is the final hurdle we clear on our way to constructing a complex discrete-continuum modelling framework capable of representing signal-mediated cell migration on growing (possibly non-standard) domains in multiple dimensions.

The study of sex allocation is one of the most successful areas in evolutionary biology: its theoretical predictions have been supported by experimental, observational and comparative approaches. Here, I develop sex allocation theory as follows: (1) I use fertility insurance theory to predict the sex ratio strategy of the malaria parasite, in response to human medical interventions that increase mortality and decrease fertility of the parasite’s various sexual stages; (2) Haplodiploidy has been suggested as a driver of the evolution of eusociality, as under this genetic system a female may be more related to her sister than to her own offspring. I examine a model considering queen versus worker control over the sex ratio of the colony and show that haplodiploidy alone does not explain the evolution of helping; (3) I follow up this study of the haplodiploidy hypothesis by examining the idea that split-sex ratios may favour the evolution of eusociality in haplodiploid species. I study the two mechanisms of split sex ratios, that are found in natural populations and may have been important in the transition to eusociality: queen virginity and queen replacement. I focus on the impact of worker reproduction by considering the effect of woker producing a fraction of the colony offspring and by considering variation in the workers’ offspring sex ratio. My analysis shows that worker reproduction does not promote the evolution of helping in haplodiploid species; (4) I examine the evolution and function of a sterile soldier caste in parasitoid wasps from the genus Encyrtidae. Two main functions have been hypothesized for the emergence of soldiers: spiteful mediation of a sex ratio conflict in mixed-sex broods, and altruistic protection and 7 facilitation of the development of relatives. I develop a model considering variation in the oviposition behaviour of females, that may produce single-sex or mixed-sex broods. I show that, in accordance with previous theory, females are expected to produce more soldiers than males, under the sex ratio conflict hypothesis. I also show that one of the consequences of this costly conflict is that females are favoured to produce single-sex broods over mixed-sex broods.

From the developing embryo to the evacuation of football stadiums, the migration and movement of populations of individuals is a vital part of human life. Such movement often occurs in crowded conditions, where the space occupied by each individual impacts on the freedom of others. This thesis aims to analyse and understand the effects of occupied volume (volume exclusion) on the movement of the individual and the population. We consider, as a motivating system, the rearrangement of individuals required to turn a clump of cells into a functioning embryo. Specifically, we consider the migration of cranial neural crest cells in the developing chick embryo. Working closely with experimental collaborators we construct a hybrid model of the system, consisting of a continuum chemoattractant and individual-based cell description and find that multiple cell phenotypes are required for successful migration. In the crowded environment of the migratory system, volume exclusion is highly important and significantly enhances the speed of cell migration in our model, whilst reducing the numbers of individuals that can enter the domain. The developed model is used to make experimental predictions, that are tested in vivo, using cycles of modelling and experimental work to give greater insight into the biological system. Our formulated model is computational, and is thus difficult to analyse whilst considering different parameter regimes. The second part of the thesis is driven by the wish to systematically analyse our model. As such, it concentrates on developing new techniques to derive continuum equations from diffusive and chemotactic individual-based and hybrid models in one and two spatial dimensions with the incorporation of volume exclusion. We demonstrate the accuracy of our techniques under different parameter regimes and using different mechanisms of movement. In particular, we show that our derived continuum equations almost always compare better to data averaged over multiple simulations than the equivalent equations without volume exclusion. Thus we establish that volume exclusion has a substantial effect on the evolution of a migrating population.

Syfte: Syftet med studien är att undersöka vilka faktorer och åtgärder som kan vara framgångsrika för säsongsförlängning hos verksamheter i skärgårdsmiljö. Metod: En kvalitativ metodansats har tillämpats genom sju intervjuer. Komplettering har gjorts med hjälp av sekundärdata.  Teoretisk referensram: Den teoretiska referensramen utgår från Conceptual approaches to seasonality causationav Goulding (2006) samt Influences on patterns of tourism seasonalityav Butler (2001). Empiri: Empirin består av fyra öppna intervjuer och tre halvstrukturerade intervjuer som genomförts med representanter från logiverksamheter i skärgården. För att komplettera materialet presenteras de berörda öarnas utbud och tillgänglighet i tabeller. Slutsatser: Verksamheter i Stockholm skärgård är beroende av naturliga och institutionella faktorer såsom väderlek, högtider och resvanor. De är främst attraktiva för besökare under sommarhalvåret och verksamheter upplever en dramatisk minskning av antalet besökare under lågsäsongen. Utbudet som finns är begränsat till sommarsäsongen då flera aktiviteter innebär utevistelse. Dock visar en del verksamheter på att de försöker hitta andra attraktioner under lågsäsong än under högsäsong för att hålla uppe besöksantalet. De handlingar som verksamheterna utför fokuserar främst på att öka tillväxten under sommarsäsong och de arbetar inte aktivt med att förlänga säsongen. Resultat visar på att de största begränsningarna som verksamheter i Stockholms skärgård har är personalbrist, naturliga orsaker samt transportmöjligheter. Det leder till att majoriteten av verksamheterna satsar på att utöka antalet besökare under högsäsongen, vilket i sin tur kan leda till problematik i bärkraften. / Purpose: The purpose of this study is to investigate and analyze actions which businesses in archipelago environments may use to successfully extend the season. Method: A qualitative research method approach has been applied through seven interviews. Completion has been made using secondary data. Theoretical framework: The theoretical framework is based on Conceptual approaches to seasonality causation from Goulding (2006) and Influences on patterns of tourism seasonalityby Butler (2001). Empericism: The empericism consists of four open interviews and three semistructured interviews conducted with representatives from different lodging businesses in the archipelago. Charts consisting information about the referred islands complete the interviews.  Conclusions: Businesses in Stockholm archipelago are dependent on natural and institutional factors such as weather, bank holidays and travel habits. Stockholm archipelago is especially attractive to visitors during the summer. Lodging businesses therefore experience a dramatic reduction in the number of visitors during the off-season. The available range is limited to the summer season when several activities are dependant on weather conditions, but some businesses show that they try to find other attractions during the low season to keep up with the declining number of visitors. The actions that the businesses take is mainly focused on increasing growth during the summer season and they are  generally not actively working to extend the seasons. Results show that the greatest limitations that the businesses face in Stockholm archipelago are staff shortages, natural causes and public transport limitations. That is, the extension of seasons being limited as the businesses mainly invest in the summer season, which in turn may lead to sustainability issues.

Syftet med denna empiriska studie är att belysa hur 10 elever i årskurs fem uppfattar miljöproblem och framtiden. Studien har tillämpat den kvalitativa metoden fokusgrupper och klarlägger begreppet hållbar utveckling samt globala insatser inom hållbar utveckling.  Vidare har hållbar utveckling i läroplanen speciellt framhävts samt tidigare forskning om elevers uppfattningar kring hållbar utveckling, miljöproblem och framtiden. Resultatet visar att elever har kunskaper om olika slags miljöproblem. Dock är nedskräpning det mest diskuterade miljöproblemet. Eleverna hade olika uppfattningar kring framtiden.  Majoriteten av eleverna uppfattade en hemsk framtid med flertal olika skadliga konsekvenser. Ett fåtal elever hade bättre förväntningar kring framtiden och menade att världens länder kommer att samarbeta kring internationella lagar för en bättre framtid. Slutligen har eleverna diskuterat hur samhället borde arbeta för att skapa en hållbar planet. / The purpose of this empirical study is to illustrate how 10 students in grade five perceive environmental problems and the future. The study has applied the qualitative method focus groups and clarifies the concept of sustainable development and global initiatives in sustainable development. The study has also highlighted sustainable development in the Swedish curriculum along with previous research on students' perceptions about sustainable development, environmental problems and the future. The result indicates that the students have knowledge of various kinds of environmental problems. However, littering was the most discussed environmental problem by the students. The students perceived contrarily about the future. The majority of students perceived a horrible future with destructive consequences. A few students had better expectations about the future and believed that nations would cooperate on international laws for a greater future. Lastly, the students discussed how the society should work to create a sustainable planet.

Inledning: Matsvinn bidrar till en negativ klimatpåverkan och svinnet av animalier, speciellt nötkött, genererar stora mängder onödigt växthusgasutsläpp per kilo. Att minska svinnet av animalier bör prioriteras för att snabbt minska växthusgasutsläppen. Syfte: Syftet är att undersöka konsumenters inställning till att köpa nötkött som frysts ner dagen innan bäst före datum har passerat i ett försök att minska köttsvinn. Vidare studeras om matrelaterade kunskaper, färdigheter och beteenden, sammanfattade i begreppet food literacy, påverkar inställningen till att köpa nötkött som frysts ner dagen innan bäst före datum har passerat. Material och metod: Data samlades in via en webbenkät och en fokusgrupp. Databearbetning och analys av den kvantitativa datan utfördes i Excel där chitvå-test användes som statistisk metod. Den kvalitativa datan transkriberades och analyserades med hjälp av kodning och tematisering. Resultat: Den kvantitativa datan visar en positiv trend där majoriteten av konsumenterna kan tänka sig att köpa nötkött som frysts ner dagen innan bäst före datum har passerat. Resultaten visar att graden av food literacy ökar med åldern. Faktorer som visar sig vara betydelsefulla för konsumenter är pris, kvalitet, förpackning och ursprung. Slutsats: Majoriteten av respondenterna oavsett ålder är positivt inställda till att köpa nötkött som frysts ner dagen innan bäst före datum har passerat. Resultatet pekar åt att andelen respondenter med hög grad av food literacy ökar med ålder och faktorer som styr vid inköp av nötkött som frysts ner dagen innan bäst före datum har passerat är pris, kvalitet, förpackning och ursprung. / Introduction: food waste contributes to a negative climate impact and the meat wastage, especially beef, generates large amounts of greenhouse gas emissions per kilogram beef. Reducing animal wastage should be a priority in order to quickly reduce greenhouse gas emissions. Aim: The aim is to investigate consumers' attitude to buying beef that has been frozen the day before the best before date has passed in an attempt to reduce the meat wastage. The study also investigates whether food-related knowledge, skills and behaviors, summarized in the concept food literacy, affect the attitude of buying beef that has been frozen the day before the best before date has passed. Method: Data was collected using a web-questionnaire and a focus group. The processing and the analysis of the data was performed in Excel using Chi-Square tests. The qualitative data was transcribed and analyzed using coding and thematization. Results: The quantitative data shows a positive trend where the majority of consumers can see themselves buying beef that has been frozen the day before the best before date has passed. The results show that the level of food literacy increases with age. Factors that prove to be important for consumers are price, quality, packaging and origin. Conclusion: The majority of respondents regardless of age are positive about buying beef. The result indicates that the proportion of respondents with a high degree of food literacy increases with age and factors that prove to be important for consumers when buying beef are price, quality, packaging and origin.

Skolverket har under år 2017 uppdaterat läroplanen där de har lyft fram ämnet teknik allt mer i undervisningen, och eleverna introduceras allt mer till teknik i grundskolan F-3. Den här studien kommer att fokusera på roboten och vad den innebär som framtidens hjälpmedel i undervisningen. I Sverige har en grundskola F-6 fått möjligheten till att pröva en robot som lärare där resultatet blev blandade reaktioner. Den här typen av robot har förmågan att samverka med människan, genom att den har programmerats till ett önskat beteende. Den har även armar och ben, samt har ett robot utseende. Studien kommer att lyfta fram tidigare forskning som har utförts gällande roboten i grundskolan och undervisningen, vilket tyder på blandade tankar kring roboten. Dessutom kommer utvalda teorier från Ellen Key och Lev Vygotskij att tas fram, eftersom de har en betydande roll för den här uppsatsen. Syftet med den här studien är att få mer kunskap om vad som kan vara betydelsen med en robot i grundskolan med perspektiv från grundskolelärare F-3, och utifrån de förutsättningar som de lärare kan ha. Uppsatsen kommer att lyfta fram intervjuer med fyra grundskolelärare F-3, som uttrycker sina åsikter kring hur de ser på roboten som ett verktyg i klassrummet. Den här studien kan bidra till ett intresse kring roboten och dess deltagande i undervsiningen. Dessutom kan den vara vägledande för alla lärare som arbetar i skolan och med elever i olika årskurser, eftersom roboten kan bli allt större i skolan. Studien kan dessutom agera som en introduktion om roboten och ge en inblick på robotens framsteg i skolvärlden, samt hur den kan bidra med olika företeelser.