Institutt for arktisk og marin biologi: Recent submissions
Now showing items 1121-1140 of 2040
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Populasjonssykluser hos hare – drevet av rovdyr og spesielt gaupe
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-27)Snøskohare – og gaupesyklusene i det boreale Nord-Amerika er et av de best kjente eksempler på populasjonssykluser. Sammenlignet med andre sykliske arter har denne syklusen en relativ konstant periode på 9–10 år. Haretettheten varierer typisk 20–30 ganger mellom topp- og bunnår. Mye økologisk forskning har ved hjelp av forskjellige metoder forsøkt å avdekke årsakene til snøskoharesyklusene, også med ... -
Hypoxia Inducible Factor 1α Inhibits the Expression of Immunosuppressive Tryptophan-2,3-Dioxygenase in Glioblastoma
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-04)Abnormal circulation in solid tumors results in hypoxia, which modulates both tumor intrinsic malignant properties as well as anti-tumor immune responses. Given the importance of hypoxia in glioblastoma (GBM) biology and particularly in shaping anti-tumor immunity, we analyzed which immunomodulatory genes are differentially regulated in response to hypoxia in GBM cells. Gene expression analyses ... -
A Multi-Pathogen Screening of Captive Reindeer (Rangifer tarandus) in Germany Based on Serological and Molecular Assays
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-20)Captive reindeer in German zoos and wildlife parks live outside their natural geographic range and are exposed to a variety of viral, bacterial and protozoan pathogens, some host-specific and some which they are not exposed to in their native habitat. Reindeer blood samples and ticks collected in 2013 from 123 reindeer at 16 different zoological facilities were available from a previous study. The ... -
When spring ephemerals fail to meet pollinators: Mechanism of phenological mismatch and its impact on plant reproduction
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-12)The flowering phenology of early-blooming plants is largely determined by snowmelt timing in high-latitude and high-altitude ecosystems. When the synchrony of flowering and pollinator emergence is disturbed by climate change, seed production may be restricted due to insufficient pollination success. We revealed the mechanism of phenological mismatch between a spring ephemeral (<i>Corydalis ambigua</i>) ... -
Maternal Photoperiodic Programming: Melatonin and Seasonal Synchronization Before Birth
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-10)This mini-review considers the phenomenon of maternal photoperiodic programming (MPP). In order to match neonatal development to environmental conditions at the time of birth, mammals use melatonin produced by the maternal pineal gland as a transplacental signal representing ambient photoperiod. Melatonin acts via receptors in the fetal pituitary gland, exerting actions on the developing medio-basal ... -
Identifying climate-sensitive infectious diseases in animals and humans in Northern regions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-14)<i>Background</i> - General knowledge on climate change effects and adaptation strategies has increased significantly in recent years. However, there is still a substantial information gap regarding the influence of climate change on infectious diseases and how these diseases should be identified. From a One Health perspective, zoonotic infections are of particular concern. The climate in Northern ... -
Pestivirus Infections in Semi-Domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus): A Retrospective Cross-Sectional Serological Study in Finnmark County, Norway.
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-26)Members of the Pestivirus genus (family <i>Flaviviridae</i>) cause severe and economically important diseases in livestock. Serological studies have revealed the presence of pestiviruses in different cervid species, including wild and semi-domesticated Eurasian tundra reindeer. In this retrospective study, serum samples collected between 2006 and 2008 from 3339 semi-domesticated Eurasian reindeer ... -
Nature-based tourism, resource dependence, and resilience of Arctic communities: framing complex issues in a changing environment
(Journal article; Tidsskriftartikkel, 2019-05-16)Current research on tourism in the Arctic has focused largely on the extent, location, and type of tourism activities that occur in the region. Recently, challenges have been identified that the tourism industry is likely to face in the wake of global changes, including climate change. Related research, conducted within and outside of the Arctic, suggests that rural communities can become economically ... -
Flexibility in a changing arctic food web: Can rough-legged buzzards cope with changing small rodent communities?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-07)Indirect effects of climate change are often mediated by trophic interactions and consequences for individual species depend on how they are tied into the local food web. Here we show how the response of demographic rates of an arctic bird of prey to fluctuations in small rodent abundance changed when small rodent community composition and dynamics changed, possibly under the effect of climate ... -
Hiding in the background: community-level patterns in invertebrate herbivory across the tundra biome
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-03)Invertebrate herbivores depend on external temperature for growth and metabolism. Continued warming in tundra ecosystems is proposed to result in increased invertebrate herbivory. However, empirical data about how current levels of invertebrate herbivory vary across the Arctic is limited and generally restricted to a single host plant or a small group of species, so predicting future change remains ... -
The radiation exposure of fish in the period of the Techa river peak contamination
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-10)Waterborne radioactive releases into the Techa River from the Mayak Production Association in Russia during 1949–1956 resulted in downstream contamination of the river ecosystem. The discharged liquid waste contained both short-lived isotopes (95Zr, 95Nb, 103,106Ru, 141,144Ce, 91Y, 89Sr and 140Ba with half-life from 3 days to 1.02 years) and the long-lived 90Sr and 137Cs (half-life - 28.79 y and ... -
Sticky mucilages and exudates of plants – putative microenvironmental design elements with biotechnological value
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-24)Plants produce a wide array of secretions both above and below ground. Known as mucilages or exudates, they are secreted by seeds, roots, leaves and stems and fulfil a variety of functions including adhesion, protection, nutrient acquisition and infection. Mucilages are generally polysaccharide‐rich and often occur in the form of viscoelastic gels and in many cases have adhesive properties. In some ... -
Assessing the effect of predator control on an endangered goose population subjected to predator-mediated food web dynamics
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-29)<ol> <li>Assessing the effectiveness of conservation actions to halt population declines is challenging when confounded by other factors. We assessed whether culling of red fox, a predator currently increasing in number in the sub‐Arctic, contributed to recent recovery of the critically endangered Fennoscandian population of Lesser White‐fronted Goose <i>Anser erythropus</i>, while controlling for ... -
High resistance to climatic variability in a dominant tundra shrub species
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-05)Climate change is modifying temperature and precipitation regimes across all seasons in northern ecosystems. Summer temperatures are higher, growing seasons extend into spring and fall and snow cover conditions are more variable during winter. The resistance of dominant tundra species to these season-specific changes, with each season potentially having contrasting effects on their growth and survival, ... -
Arctic greening and bird nest predation risk across tundra ecotones
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-01)Alarming global-scale declines of bird numbers are occurring under the changing climate, and species belonging to alpine and Arctic tundra are particularly affected. Increased nest predation appears to be involved4, but the mechanisms linking predation to climate change remain to be shown. Here we test the prediction from food web theory that increased primary productivity (greening of tundra) in a ... -
Spatial synchrony in sub-arctic geometrid moth outbreaks reflects dispersal in larval and adult life cycle stages
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-08)<OL> <LI>Spatial synchrony in population dynamics can be caused by dispersal or spatially correlated variation in environmental factors like weather (Moran effect). Distinguishing between these mechanisms is challenging for natural populations, and the study of dispersal‐induced synchrony in particular has been dominated by theoretical modelling and laboratory experiments. <LI>The goal of the ... -
Growth and metabolism of adult polar cod (Boreogadus saida) in response to dietary crude oil
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-06)The increasing human presence in the Arctic shelf seas, with the expansion of oil and gas industries and maritime shipping, poses a risk for Arctic marine organisms such as the key species polar cod (<i>Boreogadus saida</i>). The impact of dietary crude oil on growth and metabolism of polar cod was investigated in the early spring (March–April) when individuals are expected to be in a vulnerable ... -
Comparative effects of two temperatures (0 & 3 °C) on Polar cod embryonic and larval development
(Master thesis; Mastergradsoppgave, 2019-11-14)Polar cod (Boreogadus saida) are particularly vulnerable to climate change. Increasing our knowledge of polar cod development will help improve our understanding of the impact of climate change and the impacts this might have on the population. This study aimed at characterizing the development of Polar cod from fertilisation to 86 days post fertilisation (dpf) at two temperatures within their ... -
Recreational fisheries target declining populations of brown trout (Salmo trutta L.) in Northern Norway as revealed by a genome wide array of SNP markers
(Master thesis; Mastergradsoppgave, 2019-11-15)Marine recreational and commercial exploitation of salmonids often target a mixed stock consisting of genetically distinct and independent populations with varying abundances, life histories, standing genetic variation, and conservation status. In this study we use SNP markers to investigate the genetic population structure of juvenile brown trout (Salmo trutta L.) from five distinct watercourses ... -
Keeping the balance in NAD metabolism
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-09)Research over the last few decades has extended our understanding of nicotinamide adenine dinucleotide (NAD) from a vital redox carrier to an important signalling molecule that is involved in the regulation of a multitude of fundamental cellular processes. This includes DNA repair, cell cycle regulation, gene expression and calcium signalling, in which NAD is a substrate for several families of ...