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norskBrowsing Artikler, rapporter og annet (arktisk og marin biologi) by Title
Now showing items 296-315 of 1515
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Dental evidence for variation in diet over time and space in the Arctic fox, Vulpes lagopus
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-16)Studies of the effects of variation in resource availability are important for understanding the ecology of high-latitude mammals. This paper examines the potential of dental evidence (tooth wear and breakage) as a proxy for diet and food choice in Vulpes lagopus, the Arctic fox. It presents a preliminary study of dental microwear, gross wear score, and tooth breakage in a sample (n = 78 individuals) ... -
Deposit-feeding of Nonionellina labradorica (foraminifera) from an Arctic methane seep site and possible association with a methanotroph
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-30)Several foraminifera are deposit feeders that consume organic detritus (dead particulate organic material with entrained bacteria). However, the role of such foraminifera in the benthic food web remains understudied. Foraminifera feeding on methanotrophic bacteria, which are 13C-depleted, may cause negative cytoplasmic and/or calcitic δ13C values. To test whether the foraminiferal diet includes ... -
Description and Spatial Modelling of Benthic Communities Distribution in the Canadian Arctic Archipelago
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-06-29)In the Arctic, sea ice loss has already transformed the dominant sources and periodicity of primary production in some areas, raising concerns over climate change impacts on benthic communities. Considered to be excellent indicators of environmental changes, benthic invertebrates play important roles in nutrient cycling, sediment oxygenation and decomposition. However, this biological component ... -
Detecting changes in the Arctic Ecosystem – Long-Term Benthos Monitoring network for detecting changes in the Arctic benthic ecosystem (LTM-Benthos) 2017-2020
(Research report; Forskningsrapport, 2018)<i>Introduction</i>: Main purpose of this group is data exploration. For example, megafaunal community characterization, modeling of variables that influence these communities (environment, stressors, etc.). Scaling of data matters: Depending on the objectives, required resolution of the data and analyses will vary, e.g. for managing trawl closures, fine-scale analyses are required; for understanding ... -
Detecting climate signals in populations across life histories
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-20)Climate impacts are not always easily discerned in wild populations as detecting climate change signals in populations is challenged by stochastic noise associated with natural climate variability, variability in biotic and abiotic processes, and observation error in demographic rates. Detection of the impact of climate change on populations requires making a formal distinction between signals in ... -
Detection and characterization of Brucella spp. in bovine milk in small-scale urban and peri-urban farming in Tajikistan
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-15)Brucellosis is one of the most common zoonoses globally, and Central Asia remains a Brucella hotspot. The World Health Organization classifies brucellosis as a neglected zoonotic disease that is rarely in the spotlight for research and mainly affects poor, marginalized people. Urban and peri-urban farming is a common practice in many low-income countries, and it increases the incomes of families ... -
Detection of serum neutralizing antibodies to Simbu sero-group viruses in cattle in Tanzania
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-15)Background: Orthobunyaviruses belonging to the Simbu sero-group occur worldwide, including the newly recognized Schmallenberg virus (SBV) in Europe. These viruses cause congenital malformations and reproductive losses in ruminants. Information on the presence of these viruses in Africa is scarce and the origin of SBV is unknown. The aim of this study was to investigate the presence of antibodies ... -
Detection of Transgenes in Local Maize Varieties of Small-Scale Farmers in Eastern Cape, South Africa
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-12-31)Small-scale subsistence farmers in South Africa have been introduced to genetically modified (GM) crops for more than a decade. Little is known about i) the extent of transgene introgression into locally recycled seed, ii) what short and longterm ecological and socioeconomic impacts such mixing of seeds might have, iii) how the farmers perceive GM crops, and iv) to what degree approval conditions ... -
Determinants of heart rate in Svalbard reindeer reveal mechanisms of seasonal energy management
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-28)Seasonal energetic challenges may constrain an animal's ability to respond to changing individual and environmental conditions. Here, we investigated variation in heart rate, a well-established proxy for metabolic rate, in Svalbard reindeer (Rangifer tarandus platyrhynchus), a species with strong seasonal changes in foraging and metabolic activity. In 19 adult females, we recorded heart rate, ... -
Determinants of parasite distribution in Arctic charr populations: catchment structure versus dispersal potential
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-18)Parasite distribution patterns in lotic catchments are driven by the combined influences of unidirectional water flow and the mobility of the most mobile host. However, the importance of such drivers in catchments dominated by lentic habitats are poorly understood. We examined parasite populations of Arctic charr Salvelinus alpinus from a series of linear-connected lakes in northern Norway to ... -
Determination of growth, mass, and body mass index of harbour porpoises (Phocoena phocoena): Implications for conservational status assessment of populations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-27)Longitudinal data on individual growth and seasonal changes in body mass, girth, and blubber thickness are rarely available for cetaceans, making it difficult to assess their population composition and individual nutritional condition. During different time intervals from 1997 to 2020, we collected longitudinal data on length, body mass, girth,and blubber thickness from seventeen harbour porpoises ... -
Determination of Lipid Hydroperoxides in Marine Diatoms by the FOX2 Assay
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-11)Ecologically-relevant marine diatoms produce a plethora of bioactive oxylipins deriving from fatty acid oxidation, including aldehydes, hydroxy-fatty acids, epoxy-hydroxy-fatty acids, and oxo-acids. These secondary metabolites have been related to the negative effect of diatoms on copepod reproduction, causing low hatching success and teratogenesis in the offspring during periods of intense diatom ... -
Determination of plant silicon content with near infrared reflectance spectroscopy
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-09-24) -
Developing an observational design for epibenthos and fish assemblages in the Chukchi Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-14)In light of ongoing, and accelerating, environmental changes in the Pacific sector of the Arctic Ocean, the ability to track subsequent changes over time in various marine ecosystem components has become a major research goal. The high logistical efforts and costs associated with arctic work demand the prudent use of existing resources for the most comprehensive information gain. Here, we compare ... -
Developing common protocols to measure tundra herbivory across spatial scales
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-12)Understanding and predicting large-scale ecological responses to global environmental change requires comparative studies across geographic scales with coordinated efforts and standardized methodologies. We designed, applied, and assessed standardized protocols to measure tundra herbivory at three spatial scales: plot, site (habitat), and study area (landscape). The plot- and site-level protocols ... -
Development and calibration of a high dynamic range and autonomous ocean-light instrument to measure sub-surface profiles in ice-covered waters
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-23)The optical chain and logger (OptiCAL) is an autonomous ice-tethered observatory equipped with multiple light sensors for mapping the variation of light with depth. We describe the instrument and present an ensemble calibration for downwelling irradiance E<sub>PAR</sub> in [µmolm<sup>−2</sup>s<sup>−1</sup>]. Results from a long-term deployment in the Arctic Ocean demonstrate that the OptiCAL can ... -
Development and evaluation of internet-based PPGIS
(Research report; Forskningsrapport, 2014-10-15) -
Development of 14 microsatellite markers for zoonotic tapeworm dibothriocephalus dendriticus (Cestoda: Diphyllobothriidea)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-12)<i>Dibothriocephalus dendriticus</i> is one of the causative agents of the fish-borne zoonosis diphyllobothriosis. Polymorphic microsatellite markers were originally developed for future genetic studies using microsatellite library screening and next-generation sequencing (NGS). Out of 128 microsatellite candidates selected after NGS analysis, 126 yielded PCR products of the expected size. A declared ... -
Development of a bio-optical model for the Barents Sea to quantitatively link glider and satellite observations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-31)A bio-optical model for the Barents Sea is determined from a set of in situ observations of inherent optical properties (IOPs) and associated biogeochemical analyses. The bio-optical model provides a pathway to convert commonly measured parameters from glider-borne sensors (CTD, optical triplet sensor— chlorophyll and CDOM fluorescence, backscattering coefficients) to bulk spectral IOPs ... -
Developmental and Environmental Regulation of Cuticular Wax Biosynthesis in Fleshy Fruits
(Journal article; Peer reviewed, 2019-04-19)The aerial parts of land plants are covered by a hydrophobic layer called cuticle that limits non-stomatal water loss and provides protection against external biotic and abiotic stresses. The cuticle is composed of polymer cutin and wax comprising a mixture of very-long-chain fatty acids and their derivatives, while also bioactive secondary metabolites such as triterpenoids are present. Fleshy ...
