20 Works

Data from: Joint analysis of cortical area and thickness as a replacement for the analysis of the volume of the cerebral cortex

Anderson M. Winkler, Douglas N. Greve, Knut J. Bjuland, Thomas E. Nichols, Mert R. Sabuncu, Asta K. Håberg, Jon Skranes & Lars M. Rimol
Cortical surface area is an increasingly used brain morphology metric that is ontogenetically and phylogenetically distinct from cortical thickness and offers a separate index of neurodevelopment and disease. However, the various existing methods for assessment of cortical surface area from magnetic resonance images have never been systematically compared. We show that the surface area method implemented in FreeSurfer corresponds closely to the exact, but computationally more demanding, mass-conservative (pycnophylactic) method, provided that images are smoothed....

Data from: Genetic rescue of an endangered domestic animal through outcrossing with closely related breeds: a case study of the Norwegian Lundehund

Astrid V. Stronen, Elina Salmela, BK Baldursdóttir, P Berg, IS Espelien, Kirsi Järvi, Henrik Jensen, TN Kristensen, Claudia Melis, Tommaso Manenti, Hannes Lohi, Cino Pertoldi & Torsten N. Kristensen
Genetic rescue, outcrossing with individuals from a related population, is used to augment genetic diversity in populations threatened by severe inbreeding and extinction. The endangered Norwegian Lundehund dog (henceforth Lundehund) underwent at least two severe bottlenecks in the 1940s and 1960s that each left only five inbred dogs, and the approximately 1500 dogs remaining world-wide today appear to descend from only two individuals. The Lundehund has a high prevalence of a gastrointestinal disease, to which...

Data from: Assessing the dynamics of natural populations by fitting individual based models with approximate Bayesian computation

Jukka Sirén, Luc Lens, Laurence Cousseau & Otso Ovaskainen
1. Individual based models (IBMs) allow realistic and flexible modelling of ecological systems, but their parametrization with empirical data is statistically and computationally challenging. Approximate Bayesian computation (ABC) has been proposed as an efficient approach for inference with IBMs, but its applicability to data on natural populations has not been yet fully explored. 2. We construct an IBM for the metapopulation dynamics of a species inhabiting a fragmented patch network, and develop an ABC method...

Data from: Taking a trip to the shelf: behavioural decisions are mediated by the proximity to foraging habitats in the black-legged kittiwake

Signe Christensen-Dalsgaard, Roel May & Svein-Håkon Lorentsen
1. For marine top predators like seabirds, the oceans represent a multitude of habitats regarding oceanographic conditions and food availability. Worldwide, these habitats are undergoing alterations due to changes in climate and increased anthropogenic impact. This is causing a growing concern on how seabird populations might adapt to these changes. 2. Understanding how seabird populations respond to fluctuating environmental conditions and to what extent behavioural flexibility can buffer variations in food availability, can help predict...

Data from: Reversal of response to artificial selection on body size in a wild passerine

Thomas Kvalnes, Thor Harald Ringsby, Henrik Jensen, Ingerid Julie Hagen, Bernt Rønning, Henrik Pärn, Håkon Holand, Steinar Engen, Bernt-Erik Sæther & Bernt-Erik Saether
A general assumption in quantitative genetics is the existence of an intermediate phenotype with higher mean individual fitness in the average environment than more extreme phenotypes. Here we investigate the evolvability and presence of such a phenotype in wild bird populations from an eleven-year experiment with four years of artificial selection for long and short tarsus length, a proxy for body size. The experiment resulted in strong selection in the imposed directions. However, artificial selection...

Data from: Life-stage associated remodeling of lipid metabolism regulation in Atlantic salmon

Gareth Gillard, Thomas N. Harvey, Arne Gjuvsland, Yang Jin, Magny Thomassen, Sigbjorn Lien, Michael Leaver, Jacob S. Torgersen, Torgeir R. Hvidsten, Jon Olav Vik, Simen Sandve & Simen R. Sandve
Atlantic salmon migrates from rivers to sea to feed, grow and develop gonads before returning to spawn in freshwater. The transition to marine habitats is associated with dramatic changes in the environment, including water salinity, exposure to pathogens, and shift in dietary lipid availability. Many anticipatory changes in physiology occur before migration to sea, but little is known about the molecular nature of these changes. Here we use a long term feeding experiment to study...

Data from: Domestication and fitness in the wild: A multivariate view

Jarle Tufto
Domesticated species continually escaping and interbreeding with wild relatives impose a migration load on wild populations. As domesticated stocks become increasingly different as a result of artificial and natural selection in captivity, fitness of escapees in the wild is expected to decline, reducing the effective rate of migration into wild populations. Recent theory suggest that this may alleviate and eventually eliminate the resulting migration load. I develop a multivariate model of trait and wild fitness...

Data from: Effective size in density-dependent two-sex populations: the effect of mating systems

Ane Marlene Myhre, Steinar Engen, Bernt-Erik Sæther & B.-E. SAEther
Density dependence in vital rates is a key feature affecting temporal fluctuations of natural populations. This has important implications for the rate of random genetic drift. Mating systems also greatly affect effective population sizes, but knowledge of how mating system and density regulation interact to affect random genetic drift is poor. Using theoretical models and simulations, we compare Ne in short-lived, density dependent animal populations with different mating systems. We study the impact of a...

Data from: Divergent evolution and niche differentiation within the common peatmoss Sphagnum magellanicum

Narjes Yousefi, Kristian Hassel, Kjell Ivar Flatberg, Petri Kemppainen, Emiliano Trucchi, Arthur Jonathan Shaw, Magni Olsen Kyrkjeeide, Péter Szövényi & Hans Kristen Stenøien
PREMISE OF THE STUDY: Populations with phenotypic polymorphism in discrete characters may be good models for investigating genome evolution and speciation. Sphagnum magellanicum Brid. is found throughout the northern hemisphere, and despite considerable variation in morphological characters, it is considered one of the least taxonomically controversial peatmoss species. We have observed two main morphs of the species associated with different microhabitats. Here we investigated the genomic and environmental basis of this intraspecific morphological variation. METHODS:...

Data from: Sensitivity analysis of effective population size to demographic parameters in house sparrow populations

Marlene Wæge Stubberud, Ane Marlene Myhre, Håkon Holand, Thomas Kvalnes, Thor Harald Ringsby, Bernt-Erik Sæther, Henrik Jensen, Marlene Waege Stubberud & Bernt-Erik Saether
The ratio between the effective and the census population size, Ne/N, is an important measure of the long-term viability and sustainability of a population. Understanding which demographic processes that affect Ne/N most will improve our understanding of how genetic drift and the probability of fixation of alleles is affected by demography. This knowledge may also be of vital importance in management of endangered populations and species. Here, we use data from 13 natural populations of...

Data from: The plastoquinone pool of Nannochloropsis oceanica is not completely reduced during bright light pulses

Gunvor Røkke, Thor Bernt Melø & Martin Frank Hohmann-Marriott
The lipid-producing model alga Nannochloropsis oceanica has a distinct photosynthetic machinery. This organism possesses chlorophyll a as its only chlorophyll species, and has a high ratio of PSI to PSII. This high ratio of PSI to PSII may affect the redox state of the plastoquinone pool during exposure to light, and consequently may play a role in activating photoprotection mechanisms. We utilized pulse-amplitude modulated fluorometry to investigate the redox state of the plastoquinone pool during...

Data from: Parasite escape through trophic specialization in a species flock

Pascal I. Hablützel, Maarten P.M. Vanhove, Pablo Deschepper, Arnout F. Grégoir, Anna K. Roose, Filip A.M. Volckaert & Joost A.M. Raeymaekers
Adaptive radiation occurs when species diversify rapidly to occupy an array of ecological niches. Since opportunities for parasite infection and transmission may greatly vary among these niches, adaptive radiation is expected to be associated with a turnover of the parasite community. As major agents of natural and sexual selection, parasites may play a central role in host diversification. The study of parasite turnover may thus be of general relevance and could significantly improve our understanding...

Data from: Insights into the genetic architecture of morphological traits in two passerine bird species

Catarina N. S. Silva, S. Eryn McFarlane, Ingerid J. Hagen, Lars Rönnegård, Anna M. Billing, Thomas Kvalnes, Petri Kemppainen, Bernt Rønning, Thor Harald Ringsby, Bernt-Erik Sæther, Anna Qvarnström, Hans Ellegren, Henrik Jensen & Arild Husby
Knowledge about the underlying genetic architecture of phenotypic traits is needed to understand and predict their evolutionary dynamics. The number of causal loci, magnitude of their effects and location in the genome is however still largely unknown. Here we use genome-wide SNP data from two large-scale datasets on house sparrows and collared flycatchers to examine the genetic architecture of different morphological traits (tarsus length, wing length, body mass, bill depth, bill length, total and visible...

Data from: Hidden survival heterogeneity of three common eider populations in response to climate fluctuations

Loreleï Guéry, Sébastien Descamps, Roger Pradel, Sveinn Are Hanssen, Kjell Einar Erikstad, Geir W. Gabrielsen, H. Grant Gilchrist & Joël Bêty
(1) Understanding how individuals and populations respond to fluctuations in climatic conditions is critical to explain and anticipate changes in ecological systems. Most such studies focus on climate impacts on single populations without considering inter- and intra-population heterogeneity. However, comparing geographically dispersed populations limits the risk of faulty generalizations and helps to improve ecological and demographic models. (2) We aimed to determine whether differences in migration tactics among and within populations would induce inter- or...

Data from: Experimental manipulation of brood size affects several levels of phenotypic variance in offspring and parent pied flycatchers

David F. Westneat, Ariane Mutzel, Simon Bonner & Jonathan Wright
Parental provisioning of offspring should reflect selection on life history aspects of parenting and on foraging behavior. Life history and foraging theory generally make predictions about mean behavior, but some circumstances might favor changes in the variance of parent and offspring behaviors. We analyzed data on free-living pied flycatchers (Ficedula hypoleuca) experiencing a brood size manipulation. We used double hierarchical generalized linear models to investigate patterns in means and variances of provisioning, brood begging, and...

Data from: Responses of neurogenesis and neuroplasticity related genes to elevated CO2 levels in the brain of three teleost species

Floriana Lai, Cathrine E. Fagernes, Nicholas J. Bernier, Gabrielle M. Miller, Philip L. Munday, Fredrik Jutfelt & Göran E. Nilsson
The continuous increase of anthropogenic CO2 in the atmosphere resulting in ocean acidification has been reported to affect brain function in some fishes. During adulthood, cell proliferation is fundamental for fish brain growth and for it to adapt in response to external stimuli, such as environmental changes. Here we report the first expression study of genes regulating neurogenesis and neuroplasticity in brains of three-spined stickleback (Gasterosteus aculeatus), cinnamon anemonefish (Amphiprion melanopus) and spiny damselfish (Acanthochromis...

Data from: Draining the pool? Carbon storage and fluxes in three alpine plant communities

Mia Vedel Sørensen, Richard Strimbeck, Kristin Odden Nystuen, Rozalia Erzsebet Kapas, Brian J. Enquist & Bente Jessen Graae
Shrub communities have expanded in arctic and alpine tundra during recent decades. Changes in shrub abundance may alter ecosystem carbon (C) sequestration and storage, with potential positive or negative feedback on global C cycling. To assess potential implications of shrub expansion in different alpine plant communities, we compared C fluxes and pools in one Empetrum-dominated heath, one herb- and cryptogam-dominated meadow, and one Salix-shrub community in Central Norway. Over two growing seasons, we measured Gross...

Data from: Modeling time to population extinction when individual reproduction is autocorrelated

Aline Magdalena Lee, Bernt-Erik Sæther, Stine Svalheim Markussen, Steinar Engen & Bernt-Erik Saether
In nature, individual reproductive success is seldom independent from year to year, due to factors such as reproductive costs and individual heterogeneity. However, population projection models that incorporate temporal autocorrelations in individual reproduction can be difficult to parameterize, particularly when data are sparse. We therefore examine whether such models are necessary to avoid biased estimates of stochastic population growth and extinction risk, by comparing output from a matrix population model that incorporates reproductive autocorrelations to...

Data from: A multimodal image guiding system for Navigated Ultrasound Bronchoscopy (EBUS): a human feasibility study

Hanne Sorger, Erlend Fagertun Hofstad, Tore Amundsen, Thomas Langø, Janne Beate Bakeng & Håkon Olav Leira
Background: Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is the endoscopic method of choice for confirming lung cancer metastasis to mediastinal lymph nodes. Precision is crucial for correct staging and clinical decision-making. Navigation and multimodal imaging can potentially improve EBUS-TBNA efficiency. Aims: To demonstrate the feasibility of a multimodal image guiding system using electromagnetic navigation for ultrasound bronchoschopy in humans. Methods: Four patients referred for lung cancer diagnosis and staging with EBUS-TBNA were enrolled in the...

Data from: Demographic influences of translocated individuals on a resident population of house sparrows

Peter S. Ranke, Sigrun Skjelseth, Henrik Pärn, Ivar Herfindal, Åsa Alexandra Borg Borg, Bård Gunner Stokke, Thomas Kvalnes, Thor Harald Ringsby, Bernt-Erik Sæther, Henrik Jensen & Bernt-Erik Saether
Translocation of individuals from source populations to augment small populations facing risk of extinction is an important conservation tool. Here we examine sex-specific differences between resident and translocated house sparrows Passer domesticus in reproductive success and survival, and the contribution of translocated individuals to the growth of a local population. We found evidence for assortative mating based on origin revealed by fewer parentages between translocated males and resident females than expected, and the total number...

Registration Year

  • 2017

Resource Types

  • Dataset


  • Norwegian University of Science and Technology
  • University of Helsinki
  • Norwegian Institute for Nature Research
  • University of Oslo
  • Nord University
  • Dalarna University
  • Ghent University
  • Duke University
  • Université Paul-Valéry Montpellier
  • Aarhus University