The derivation of the functional response in a prey-predator system with active group defense

Group defense against predator attacks are common for prey species. Some group defense mechanisms are more passive, like swarm confusion. In this thesis the focus is an active type of group defense where the prey fight back against the attacking predator as a group. The aim of this thesis is to formulate a model with active groups defense and to mechanistically derive and analyse the functional response arising from it. The motivation is to understand the impact of this special type of group defense on the functional response of the predator, and hence on the whole dynamics of the model. Some theory about prey-predator models, the functional response and tools for analysing dynamical systems are presented as background first. Following this, the model is formulated from the individual level processes and the functional response derived using the method of time-scale separation. Finally, two special cases of the model are analysed. In the model, the defense of the prey is modelled as a coagulation and fragmentation process, where the prey can join the fight to protect the individual that is being attacked. These fights become clusters where the attacking predator is the coagulation kernel. The clusters can grow or shrink by one prey joining or leaving at a time, or the cluster breaking up completely due to success of either the attack or the defense. This type of coagulation and fragmentation process can be seen as a generalization of the Becker-Döring equations, where the clusters are homogenous groups and the groups can also only grow and shrink by one individual at a time. The cluster dynamics truncated with a maximum size for the clusters was found to have a unique and stable equilibrium for arbitrarily large maximum cluster sizes in both special cases of the model. The stability analysis for cluster dynamics with no maximum cluster size was not successful, even though there is reason to believe the results for the truncated system is generalizable to that case. The functional response was found to take a dome-shaped form, decreasing to zero under certain circumstances, or the form of Holling type II functional response. The determining factor for which type of functional response the model gives rise to is whether the predator’s attack rate is dependent on the cluster size or not. The same dependence of the form of the functional response on the attack rate was found to hold in both special cases of the model

From notochord to vertebral column: studies on Atlantic salmon (Salmo salar L.)

The notochord initially form a single-cell file stage of chordoblasts covered by a three layered sheath comprising a basal lamina, a main collagenous layer and an external elastic membrane. During early ontogeny, the collagenous layer of the sheath goes through changes in configuration from a circular orientation, with fibres oriented perpendicular to the long axis, and to a lamellar organization where alternating layers of parallel collagen fibres form helices, with a tangent angle of 75-80° to the long axis. The shift in collagen arrangement is taking place shortly after hatching and may reflect an adaptation of the notochord to functional demands related to stage of development. The serrated surfaces of the elastica externa encasing the notochord seem to provide an interconnection between the notochord and the myosepta, with a function related to transmission of force from the musculature. The subsequent segmentation process leading to formation of vertebral and intervertebral regions seems to be initiated within the notochord through formation of cellular chordoblast segments. Formation of the cellular segments is closely followed by a segmental pattern of ALP activity within the chordoblast layer and formation of mineralized chordacentra within the collagenous layer of the notochord sheath. Development of the vertebral column thus seem to involve a dual segmentation where notochord derived chordacentra define the vertebral segments and the sclerotome external to the notochord provide further growth to the vertebrae. The salmon vertebral column comprises notochord and sclerotome derived structures that tightly interconnect the vertebrae and the intervertebral regions. There are four distinct layers of bone and mineralized tissues that form the vertebral body. The two inner layers comprise the chordacentrum (mineralization of the notochord sheath) and the inner layer of the amphicoel (mineralization of the intervertebral ligament). The third layer is deposited by osteoblasts, forming the main portion of the amphicoelous centrum, and on its external surface, trabecular bone is deposited. The three inner layers have a lamellar organization, with collagen matrixes oriented perpendicular from layer to layer, while the fourth layer has a woven structure. The 6 layers also differ in osteocyte content. The notochord remains within the full length of the vertebral column and form the inner part of the intervertebral ligament. The sclerotomal external portion of the ligament is incorporated in the vertebrae as it is covered by bone during vertebral growth, while remaining unmineralized intervertebrally. The present studies on salmon shows that the notochord constitutes the main axial support during embryonic and larval stages and that the enforcing rearrangement of the collagen layer of the notochord sheath seems to be important for the properties of the notochord as a fibre-wound hydrostatic skeleton. The notochord further reinforces through formation of chordacentra, generating the segmental pattern of the vertebral column, while sclerotomal tissue external to the notochord provides further growth to the vertebrae and intervertebral structures

Quality of life in persons with hearing loss: The importance of psychological variables and hearing loss severity

Hearing loss (HL) is a prevalent condition, representing health and social challenges for a substantial number or of people globally. Up to 15% of the world’s adult population is estimated to suffer from HL. As most people with HL suffers from age related HL, i.e. presbyacusis, the growing proportion of older people in the population, will lead to a substantial increase in the number of persons with hearing loss in the near future. In addition to the effect this will have on each individual’s life, it also represents huge social consequences. The overall objective of this thesis was to investigate the relationship between HL, general/generic and communication-specific (Health Related) Quality of Life ((HR)QoL). As supporting aims, distress, personality and choice of coping in HL patients was also investigated. In paper I, we aimed to further develop the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire for the self-assessment of communication ability. We investigated the psychometric properties of the Norwegian version of the questionnaire applied to controls and a group of persons with various degrees of HL seeking HA. The findings indicate that the questionnaire is a valid measure of communication ability in both quiet and adverse listening conditions for participants with and without HL. This questionnaire was applied in paper III and paper IV. Paper II presents a systematic literature review of studies investigating generic QoL in patients with HL. As an additional aim, we also included studies that addressed distress, mood, anxiety and HL. The findings in this review suggests that HL is associated with reduced generic QoL. However, the findings were equivocal, with some studies suggesting a strong relationship between HL and QoL, while others found no such relations. We also found that hearing aids (HA) seems to improve general QoL within the first year and that HL is a risk factor for distress. Conducting a systematic literature review developed our understanding of the field, and the findings enabled us to develop methods and hypothesis applied in paper III and IV. In the third paper we studied the relationship between general QoL, the APHAB response pattern and HL. The study found that the QoL level in persons with HL seems to be close to what seen in the general population, but higher than what is seen in many chronic serious diseases. Patients with unilateral HL reported slightly worse social function and more fatigue than patients with bilateral HL. Self- assessed communication ability correlated with general QoL scores. We also found that best pure tone average, but also cognitive and physical QoL function were associated to APHAB scores. This study concludes that general QoL scores among HL individuals seems to be relatively close to what have been reported in the general population. In paper IV we investigated the importance of personality and choice of coping on QoL, distress and reported communication ability in persons with HL. Significant correlations were found between APHAB, HRQoL, distress scores on the one side and personality and coping style on the other side. The results suggests that employed coping style, distress/HRQoL and personality were closely associated to each other in this patient group. Patient-reported communication ability was associated to PTA (best ear) and personality. In overall conclusion, general QoL among patients with HL seeking HA seems to be close to population levels. Distress scores may be slightly elevated compared to population norms. QoL and distress scores and interestingly APHAB scores seems also to depend on personality scores

From notochord to vertebral column: studies on Atlantic salmon (Salmo salar L.)

The notochord initially form a single-cell file stage of chordoblasts covered by a three layered sheath comprising a basal lamina, a main collagenous layer and an external elastic membrane. During early ontogeny, the collagenous layer of the sheath goes through changes in configuration from a circular orientation, with fibres oriented perpendicular to the long axis, and to a lamellar organization where alternating layers of parallel collagen fibres form helices, with a tangent angle of 75-80° to the long axis. The shift in collagen arrangement is taking place shortly after hatching and may reflect an adaptation of the notochord to functional demands related to stage of development. The serrated surfaces of the elastica externa encasing the notochord seem to provide an interconnection between the notochord and the myosepta, with a function related to transmission of force from the musculature. The subsequent segmentation process leading to formation of vertebral and intervertebral regions seems to be initiated within the notochord through formation of cellular chordoblast segments. Formation of the cellular segments is closely followed by a segmental pattern of ALP activity within the chordoblast layer and formation of mineralized chordacentra within the collagenous layer of the notochord sheath. Development of the vertebral column thus seem to involve a dual segmentation where notochord derived chordacentra define the vertebral segments and the sclerotome external to the notochord provide further growth to the vertebrae. The salmon vertebral column comprises notochord and sclerotome derived structures that tightly interconnect the vertebrae and the intervertebral regions. There are four distinct layers of bone and mineralized tissues that form the vertebral body. The two inner layers comprise the chordacentrum (mineralization of the notochord sheath) and the inner layer of the amphicoel (mineralization of the intervertebral ligament). The third layer is deposited by osteoblasts, forming the main portion of the amphicoelous centrum, and on its external surface, trabecular bone is deposited. The three inner layers have a lamellar organization, with collagen matrixes oriented perpendicular from layer to layer, while the fourth layer has a woven structure. The 6 layers also differ in osteocyte content. The notochord remains within the full length of the vertebral column and form the inner part of the intervertebral ligament. The sclerotomal external portion of the ligament is incorporated in the vertebrae as it is covered by bone during vertebral growth, while remaining unmineralized intervertebrally. The present studies on salmon shows that the notochord constitutes the main axial support during embryonic and larval stages and that the enforcing rearrangement of the collagen layer of the notochord sheath seems to be important for the properties of the notochord as a fibre-wound hydrostatic skeleton. The notochord further reinforces through formation of chordacentra, generating the segmental pattern of the vertebral column, while sclerotomal tissue external to the notochord provides further growth to the vertebrae and intervertebral structures

Female autonomy – literary analysis of Jane Austen’s protagonists versus Caitlin Moran and the modern woman

This thesis has one major purpose: to examine how women’s autonomy over their own lives has changed from Jane Austen’s writing until Caitlin Moran’s memoir in 2011. The thesis will show through literary analysis how expectations toward women have changed from the 1800s until today. The novels in focus in this thesis is Pride and Prejudice and Mansfield Park by Jane Austen and the memoir How To Be a Woman by Caitlin Moran. The literary analysis will focus on how a woman’s family and society controlled the way she lived her life contrary to how family and society control, or lack of control, in Caitlin Moran’s life. Austen’s protagonists will represent life in Austen’s time, while Caitlin Moran will represent the modern woman. To be able to conduct this investigation it is important to understand what society expects from women both in Austen’s time and today. Chapter 2 will explain the feminist and patriarchal theories I will be using to explain this view on women. Furthermore, the theoretical orientation chapter will explain why marriage and money was so important for Austen’s protagonists. The characters in focus are Elizabeth Bennet in Pride and Prejudice and Fanny Price in Mansfield Park. This thesis will also show how Elizabeth and Fanny show their independence by fighting against these expectations. In chapter 5 women’s role in modern society will be explained alongside Caitlin Moran. This study will show how the three major feminist waves from the 1800s until today, paved the way for the independent modern woman. This thesis will also show how freedom from family and economical independence are the main reasons for the modern woman to have autonomy over her life. The protagonists Elizabeth and Fanny are not able to have economic freedom. They will need to marry to achieve this. Their families are important in making this happen. To be able to make a good match they will need connections. They will also need a high social ranking to be able to secure a rich man. Caitlin Moran has access to education and is able to secure a job and an income. The aim of the discussion is to show, through literary analysis of the books, how social expectations, access to education and financial independence have changed over the decades

Neighborhood variation in early adult educational outcomes: The case of Norway

Individuals originating in different neighborhoods fare differently in later life. Part of this is because families sort non-randomly over the urban landscape; different types of families live in systematically different neighborhoods. Another part of the explanation is that children in different neighborhoods are exposed to different urban opportunity structures. The opportunity structure can exert its influence through social interactive, environmental and institutional factors. Using a multi-level framework applied to a Norwegian register-based data set with complete coverage of 1986-1992 cohorts with siblings, we decompose the variation in high school completion and in enrollment in higher education at age 22 into variances at the levels of family and neighborhood occupied at age seven. The variations in both outcome variables among young adults raised in different neighborhoods are substantively important. The gap in expected high school completion rates between children raised in the upper and lower quartiles of the neighborhood distribution is eleven percentage-points; the equivalent gap in being enrolled in higher education is 16 percentage points. We also find substantial heterogeneity in this neighborhood variation; for example, boys are more vulnerable to neighborhood variations, while children residing with both parents at the age of seven are less vulnerable. We argue that the large variation across neighborhoods in educational outcomes of young adults should be of concern for policymakers. It can both imply a suboptimal utilization of human resources and it can feed into inequalities later on in the lifecourse and harm social cohesion thereby

Supply flexibility in the shale patch: Evidence from North Dakota

This paper provides new results to the literature, showing that output flexibility in oil production depends on the extraction technology. In particular, constructing a novel well-level monthly production dataset covering more than 16,000 crude oil wells in North Dakota, we find supply elasticity of shale wells to be positive and in the range of 0.3–0.9, depending on wells and firms characteristics. We find no such responses for conventional wells. We interpret the supply pattern of shale oil wells to be consistent with the Hotelling theory of optimal extraction. Reserves are an inventory, and the decision to produce is an intertemporal choice of when to draw down below-ground inventory.publishedVersio

VATDIS Web Mapping - A Report on the Application of Open Standards and Open Architecture in Geospatial Interoperability for Emergency Management

This report provides an overview of the web mapping activities carried out in the VATDIS action in 2007. These web mapping activities aimed at integrating the work done for the Orchestra, Floodsite and Preview IP into one single demonstrator. In the main section of this report an outline is given of the reasons for integrating the projects and the contents of this integration. The report should be seen as a summary of the technical choices made in order to accomplish this integration. The annexes on this report help the more technical reader to understand the design of the demonstrator and to duplicate it for its own purposes.JRC.G.7-Traceability and vulnerability assessmen

Hackere/Crackere

Denne masteroppgaven går ut på å finne ut hva som karakteriserer hackere og crackere. Oppgaven tar opp temaer som begrepsdefinering, motivasjoner, moral, metoder, organisering og informasjonsflyt. For å finne ut av dette har jeg brukt kvalitative forskningsmetoder. Datamaterialet er samlet inn gjennom en rekke intervjuer av dataeksperter, hackere og crackere, samt noe sekundærlitteratur. Det finnes mange måter å definere hackere og crackere på, og mange er uenige i hvordan termene skal brukes. Jeg omtaler hackere personer som ikke er involvert i noen form for kriminelle handlinger, og crackere som personer som oppnår eller prøver å oppnå uautorisert tilgang til systemer og informasjon. Jeg definerer hackerne som de «etiske» og lovlydige, mens crackerne blir de «uetiske» og kriminelle

Protestbevegelse eller nytt kirkesamfunn?

Denne artikkelen handler om relasjonen mellom Den norske kirke og den delen av den læstadianske bevegelsen som kalles de førstefødte. I 2000 besluttet de førstefødte å la sine predikanter forrette dåp og nattverd i bevegelsens egne forsamlingshus, og innenfor rammen av forsamlingenes ordinære møter. Vedtaket var et sterkt signal om et oppbrudd fra kirkens sakramentsforvaltning. Artikkelen sikter mot å klargjøre hva som likevel holder bevegelsen tilbake i forhold til å etablere seg som et eget kirkesamfunn