Browsing Institutt for matematiske fag by Author "Jensen, Henrik"
Now showing items 1-12 of 12
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A Continuous-Time, Discrete-Space Statistical Model for Estimating Dispersal Rate Applied to a Population of House Sparrows (Passer Domnesticus) in Northern Norway
Drahus, Kristin Mathilde (Master thesis, 2015)How individuals move and interact with each other is a complex matter. Even so, the knowledge of how such movements and interactions happen is important to understand in order to be able to keep genetic variation and ... -
Animal Models and Integrated Nested Laplace Approximations
Holand, Anna Marie; Steinsland, Ingelin; Martino, Sara; Jensen, Henrik (Journal article; Peer reviewed, 2013)Animal models are generalized linear mixed models used in evolutionary biology and animal breeding to identify the genetic part of traits. Integrated Nested Laplace Approximation (INLA) is a methodology for making fast, ... -
Animal models with group-specific additive genetic variances: extending genetic group models
Muff, Stefanie; Niskanen, Alina Katariina; Saatoglu, Dilan; Keller, Lukas; Jensen, Henrik (Journal article; Peer reviewed, 2019)Background The animal model is a key tool in quantitative genetics and has been used extensively to estimate fundamental parameters, such as additive genetic variance or heritability. An implicit assumption of animal ... -
Endoparasite infection has both short- and long-term negative effects on reproductive success of female house sparrows, as revealed by faecal parasitic egg counts
Holand, Håkon; Jensen, Henrik; Tufto, Jarle; Pärn, Henrik; Sæther, Bernt-Erik; Ringsby, Thor Harald (Journal article; Peer reviewed, 2015)Parasites have the potential to severely reduce host reproductive success. However, the effects of endoparasites on reproductive success have not received the same amount of attention as the effects of parasites on host ... -
Genomic estimation of quantitative genetic parameters in wild admixed populations
Aase, Kenneth; Jensen, Henrik; Muff, Stefanie (Peer reviewed; Journal article, 2022)1. Heritable genetic variation among free-living animals or plants is essential for populations to respond to selection and adapt. It is therefore important to be able to estimate additive genetic variance VA, which can ... -
Lower survival probability of house sparrows severely infected by the gapeworm parasite
Holand, Håkon; Jensen, Henrik; Tufto, Jarle; Soliman, Mustafa M.; Pärn, Henrik; Sæther, Bernt-Erik; Ringsby, Thor Harald (Journal article; Peer reviewed, 2014)The effect of parasites in natural populations has received increasing attention in recent years. Studies have shown that parasites may play an important part in population ecology due to their potential effects on host ... -
On estimation and identifiability issues of sex-linked inheritance with a case study of pigmentation in Swiss barn owl (Tyto alba)
Larsen, Camilla Thorrud; Holand, Anna Marie; Jensen, Henrik; Steinsland, Ingelin; Roulin, Alexandre (Journal article; Peer reviewed, 2014)Genetic evaluation using animal models or pedigree-based models generally assume only autosomal inheritance. Bayesian animal models provide a flexible framework for genetic evaluation, and we show how the model readily can ... -
Parasite prevalence increases with temperature in an avian metapopulation in northern Norway
Holand, Håkon; Jensen, Henrik; Kvalnes, Thomas; Tufto, Jarle; Pärn, Henrik; Sæther, Bernt-Erik; Ringsby, Thor Harald (Peer reviewed; Journal article, 2019)Climate and weather conditions may have substantial effects on the ecology of both parasites and hosts in natural populations. The strength and shape of the effects of weather on parasites and hosts are likely to change ... -
Quantitative genetic modeling and inference in the presence of nonignorable missing data
Steinsland, Ingelin; Larsen, Camilla Thorrud; Roulin, Alexandre; Jensen, Henrik (Journal article; Peer reviewed, 2014)Natural selection is typically exerted at some specific life stages. If natural selection takes place before a trait can be measured, using conventional models can cause wrong inference about population parameters. When ... -
Spatial variation in senescence rates in a bird metapopulation
Holand, Håkon; Kvalnes, Thomas; Gamelon, Marlène; Tufto, Jarle; Jensen, Henrik; Pärn, Henrik; Ringsby, Thor Harald; Sæther, Bernt-Erik (Journal article, 2016)Investigating factors which affect the decline in survival with age, i.e. actuarial senescence, is important in order to understand how demographic rates vary in wild populations. Although the evidence for the occurrence ... -
Spatial variation in the evolutionary potential and constraints of basal metabolic rate and body mass in a wild bird
Nafstad, Ådne Messel; Rønning, Bernt; Aase, Kenneth; Ringsby, Thor Harald; Hagen, Ingerid Julie; Ranke, Peter Sjolte; Kvalnes, Thomas; Stawski, Clare; Räsänen, Katja; Sæther, Bernt-Erik; Muff, Stefanie; Jensen, Henrik (Peer reviewed; Journal article, 2023)An organism's energy budget is strongly related to resource consumption, performance, and fitness. Hence, understanding the evolution of key energetic traits, such as basal metabolic rate (BMR), in natural populations is ... -
Temporal and spatial variation in prevalence of the parasite Syngamus trachea in a metapopulation of House Sparrows (Passer domesticus)
Holand, Håkon; Jensen, Henrik; Tufto, Jarle; Sæther, Bernt-Erik; Ringsby, Thor Harald (Journal article, 2013)When investigating parasite–host dynamics in wild populations, a fundamental parameter to investigate is prevalence. This quantifies the percentage of individuals infected in the population. Investigating how prevalence ...