50 research outputs found
Genetic structuring in Atlantic haddock contrasts with current management regimes
The advent of novel genetic methods has made it possible to investigate population structure and connectivity in mobile marine fish species: knowledge of which is essential to ensure a sustainable fishery. Haddock (Melanogrammus aeglefinus) is a highly exploited marine teleost distributed along the coast and continental shelf on both sides of the North Atlantic Ocean. However, little is known about its population structure. Here, we present the first study using single-nucleotide polymorphism (SNP) markers to assess the genetic population structure of haddock at multiple geographic scales, from the trans-Atlantic to the local (fjord) level. Genotyping 138 SNP loci in 1329 individuals from 19 locations across the North Atlantic revealed three main genetic clusters, consisting of a Northwest Atlantic cluster, a Northeast Arctic cluster, and a Northeast Atlantic cluster. We also observed a genetically distinct fjord population and a pattern of isolation by distance in the Northeast Atlantic. Our results contrast with the current management regime for this species in the Northeast Atlantic, as we found structure within some management areas. The study adds to the growing recognition of population structuring in marine organisms in general, and fishes in particular, and is of clear relevance for the management of haddock in the Northeast Atlantic.publishedVersionPaid open acces
Experimental transmission of piscine orthoreovirus-1 (PRV-1) in different life stages of Atlantic salmon (Salmo salar) and brown trout (Salmo trutta)
Piscine orthoreovirus -1 (PRV-1) causes the disease heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon, and the virus has been detected in wild anadromous Atlantic salmon and brown trout. However, the infection prevalence, viral kinetics, and disease severity in different life stages of Atlantic salmon and brown trout are unknown. The current study aimed to evaluate and compare susceptibility to PRV-1 infection and development of HSMI in different life stages of anadromous Atlantic salmon (Salmo salar) and brown trout (Salmo trutta). We challenged Atlantic salmon and brown trout fry, parr, and post-smolts with PRV-1 by bath, cohabitation, or IP injection. The kinetics of viral infection and disease development were evaluated by RT-qPCR, in situ hybridization, and histology. Our results indicated that PRV-1 infection prevalence and viral kinetics depend on the developmental stage and challenge method in both Atlantic salmon and brown trout. All developmental stages of Atlantic salmon and brown trout can be infected with PRV-1. However, brown trout showed a lower infection prevalence, with positive cases exhibiting only mild infections without any pathological changes in the target organs, while all life stages of Atlantic salmon developed heart lesions characteristic of HSMI. These results strongly suggest that brown trout are less susceptible to PRV-1 infection than Atlantic salmon and further confirm the species-specific susceptibility and disease development for PRV-1 infection
Highly mixed impacts of near-future climate change on stock productivity proxies in the North East Atlantic
Impacts of climate change on ocean productivity sustaining world fisheries are predominantly negative but vary greatly among regions. We assessed how 39 fisheries resources—ranging from data-poor to data-rich stocks—in the North East Atlantic are most likely affected under the intermediate climate emission scenario RCP4.5 towards 2050. This region is one of the most productive waters in the world but subjected to pronounced climate change, especially in the northernmost part. In this climate impact assessment, we applied a hybrid solution combining expert opinions (scorings)—supported by an extensive literature review—with mechanistic approaches, considering stocks in three different large marine ecosystems, the North, Norwegian and Barents Seas. This approach enabled calculation of the directional effect as a function of climate exposure and sensitivity attributes (life-history schedules), focusing on local stocks (conspecifics) across latitudes rather than the species in general. The resulting synopsis (50–82°N) contributes substantially to global assessments of major fisheries (FAO, The State of World Fisheries and Aquaculture, 2020), complementing related studies off northeast United States (35–45°N) (Hare et al., PLoS One, 2016, 11, e0146756) and Portugal (37–42°N) (Bueno-Pardo et al., Scientific Reports, 2021, 11, 2958). Contrary to prevailing fisheries forecasts elsewhere, we found that most assessed stocks respond positively. However, the underlying, extensive environmental clines implied that North East Atlantic stocks will develop entirely different depending upon the encountered stressors: cold-temperate stocks at the southern and Arctic stocks at the northern fringes appeared severely negatively impacted, whereas warm-temperate stocks expanding from south were found to do well along with cold-temperate stocks currently inhabiting below-optimal temperatures in the northern subregion.publishedVersio
Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures
Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo
Effekter av krisekommunikasjon for omdømmet : en casestudie av Gilde under E.coli-krisen
Formålet med denne masterutredningen er å få en dypere forståelse for hva som kan
karakteriseres som god krisekommunikasjon, samt hvilken virkning krisekommunikasjon kan
ha på en virksomhets omdømme under og etter en krise.
Utredningen benytter to hovedteorier om krisekommunikasjon; Benoits image repair
strategy og Coombs teori om situasjonsbestemt krisekommunikasjon (SCCT). Det trekkes også inn generell teori om omdømme og tillit.
Utredningen gjennomføres som en casestudie av Gildes krisekommunikasjon under e.coli-krisen i 2006. Analyse av krisekommunikasjonen foretas gjennom kvalitativ innholdsanalyse
av kriseperiodens nyhetsartikler, mens diskusjonen av omdømmeeffekter benytter
sekundærdata fra omdømmeundersøkelser og rapporter. Stakeholdere er avgrenset til
forbrukere og media.
Vi argumenterer for at Gildes krisekommunikasjon i stor grad bidro til å gjøre Gildes omdømmefall kortvarig. Utredningen avsluttes med implikasjoner og forslag til videre forskning
Positive handling in late pregnancy and the consequences for maternal behaviour and production in sows
Abstract Fifty-two sows were subjected to a human approach test (HAT) at 2 weeks, and again at 3-4 days, before expected farrowing. Latency to contact and time spent exploring the experimenter, and overall confidence score (1 = low to 6 = high) were recorded. Fifty percentage of the sows received positive handling for 1 min twice daily, 5 days a week from first HAT to farrowing, whilst the others were controls without additional handling. Behaviour was video-recorded from 2 days before until 4 days after farrowing. In the first HAT, 37% of sows immediately made contact with the experimenter (score 6), whereas 20% withdrew (scores 1 and 2). To give the sows a positive association to the handler, feed rewards were given. The sows accepted a feed nut from the hand significantly sooner than petting (P = 0.05). After 2 weeks of handling, the confidence score had increased significantly (P < 0.001), but a similar tendency occurred for controls (P = 0.06). For the most fearful sows (scores 1 and 2), the handling procedure resulted in a major increase in confidence score (P < 0.001). There were no significant differences in piglet mortality or early lactation piglet weight gain between treatments. In the control group, sows with a high (6) initial confidence score tended to have shorter farrowing duration than sows with a low (1 or 2) initial confidence score (P = 0.07). with a low initial confidence score, the positive handling resulted in a shorter farrowing duration, but the effect was not significant. In the last 8 h before farrowing, positively handled sows also tended to rest more than sows in the control group. # 2005 Published by Elsevier B.V