| 1. |
- Andersson, Anna, et al.
(författare)
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Does fishery activity affect local tourism? Evidence from Denmark
- 2024
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Ingår i: Marine Policy. - 0308-597X .- 1872-9460. ; 161
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Tidskriftsartikel (refereegranskat)abstract
- Fishery and tourism coexist in many harbors. Active fishing vessels may attract tourists, which may also provide income to hotels and restaurants. This paper analyzes whether fisheries affect tourism by investigating the effect of the presence of active vessels on overnight stays in coastal areas of Denmark. The analysis is based on monthly panel data from 2016 to 2021 divided into postal code areas. Estimating a double logarithmic model accounting for fixed effects, it is found that when the number of fishing vessels belonging to a harbor in a postal code area increases by 1%, overnight stays in the same area increase by 0.11%, and when the number of fishing vessels landing in an area increases by 1%, overnight stays increase by 0.08%. Our results suggest that tourism is significantly positively affected by having active fishing vessels landing in local harbors. This implies that by considering the interactive effects of fisheries and tourism when designing fisheries policy, society might attain economic gains, potentially resulting in a larger fleet than what would be optimal solely from a fisheries perspective.
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| 2. |
- Andersson, Anna, et al.
(författare)
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Finns det ett samband mellan yrkesfiske och turism?
- 2021
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Rapport (populärvet., debatt m.m.)abstract
- Det finns en uttalad politisk vilja att stödja det lokala fisket i Sverige. Ett skäl till detta är att levande fiskehamnar kan locka turister till kustnära samhällen. I denna studie analyserar vi kopplingen mellanyrkesfiske och antalet gästnätter på hotell, vandrarhem och stugbyar.* Vi finner att antalet gästnätter är högre i kustkommuner med mer yrkesfiske.* Vi finner däremot inte stöd för att yrkesfisket genererar fler gästnätter. Detta gäller både fiske generellt och småskaligt fiske.* Även om det inte går att säga att yrkesfiske generellt lockar turister, kan fisket vara viktigt för turismen ienskilda kommuner.
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| 3. |
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| 4. |
- Andersson, Anna, et al.
(författare)
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Local Fisheries and Thriving Harbors: Is There a Value for the Tourism Sector?
- 2021
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Ingår i: Marine Resource Economics. - : University of Chicago Press. - 0738-1360 .- 2334-5985. ; 36:2
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Tidskriftsartikel (refereegranskat)abstract
- Local commercial fishing is often claimed to attract tourists to coastal communities. We investigate the impact of local fishing on tourism demand, measured as overnight stays, in Sweden. Using municipal-level data for the period 1998–2015, we perform a quantitative analysis using ordinary least squares (OLS) as well as panel-data methods that take unobserved heterogeneity between municipalities into account. A statistically significant positive relationship is found between fishing and overnight stays when OLS is used as the estimation method. The relationship is also found to be stronger on the west and south coasts of Sweden, regions where the fishing cultural heritage is particularly recognized. However, when using panel-data methods that introduce fixed effects for municipalities, we are not able to find a stable significant relationship between fishing and tourism. We therefore find it difficult to claim that fishing promotes tourism, at least when tourism is measured as overnight stays.
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| 5. |
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| 6. |
- Blomquist, Emil, et al.
(författare)
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Evidence of attraction between charge carriers in a doped Mott insulator
- 2021
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Ingår i: Physical Review Research. - : American Physical Society (APS). - 2643-1564. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Recent progress in optically trapped ultracold atomic gases is now making it possible to access microscopic observables in doped Mott insulators, which are the parent states of high-temperature superconductors. This makes it possible to address longstanding questions about the temperature scales at which attraction between charge carriers are present, and their mechanism. Controllable theoretical results for this problem are not available at low temperature due to the sign problem. In this work, we make important progress with this problem by employing worm-algorithm Monte Carlo, which allows us to obtain completely unbiased results for two charge carriers in a Mott insulator. Our method gives access to lower temperatures than what is currently possible in experiments, and provides evidence for attraction between dopants at a temperature scale that is now feasible in ultracold atomic systems. We also report on spin correlations in the presence of charge carriers, which are directly comparable to experiments.
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| 7. |
- Blomquist, Emil
(författare)
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Strong Correlation Effects in Bosonic and Fermionic Systems Through an Unbiased Quantum Monte Carlo Approach
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Strongly interacting many-body quantum systems constitute some of the most challenging problems in physics, and exact analytical solutions are rare. In this thesis, we will investigate the models of two such systems numerically using the unbiased worm-algorithm Monte Carlo method.The first model is the t-J model, which describes strongly correlated lattice electrons and is thought to capture the essential physics of high-temperature superconductors. Of particular interest to us is the emergent magnetic polaron studied in the first two papers. The microscopic pairing mechanism between these quasiparticles remains one of the most outstanding open questions in condensed matter physics.The second model is an extended multi-component Bose--Hubbard model, which describes lattice bosons of multiple species. This model is essential to the third paper, in which we demonstrate a novel superfluid phenomenon in the form of a dissipationless drag effect that couples the different superfluid components of a superfluid mixture in a noncollinear fashion. Dissipationless drag is a fundamental effect present in a diverse set of physical systems. In the fourth paper, we further use the Bose--Hubbard model to study other new superfluid phenomena that arise when the number of superfluid components is increased.A general introduction to the research field is first given in the thesis, after which some prerequisites are refreshed. Then essential concepts are introduced, and the numerical method is outlined and benchmarked. Following that is a summary of the research carried out.
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| 8. |
- Blomquist, Emil, et al.
(författare)
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Unbiased description of magnetic polarons in a Mott insulator
- 2020
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Ingår i: Communications Physics. - : Springer Nature. - 2399-3650. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Polarons are elementary quasi-particles characterizing several interacting many-body quantum systems. The authors present an unbiased Quantum Monte Carlo simulation of a magnetic polaron in a t-J model at low-temperature, and find excellent agreement with a recent experimental realization in the framework of cold-atoms systems. Polarons are among the most elementary quasiparticles of interacting quantum matter, consisting of a charge carrier dressed by an excited background. In Mott insulators, they take the form of a dopant surrounded by a distorted spin-background. Despite the fundamental importance of polarons for the electronic structure of strongly correlated systems, access to their internal structure was only recently realized in experiments, while controllable theoretical results are still lacking due to the sign problem. Here we report unbiased high-precision data obtained from worm-algorithm Monte Carlo that reveal the real-space structure of a polaron in thet-Jmodel deep inside the region where the sign problem becomes significant. These results are directly comparable to recent quantum gas microscopy experiments, but give access to significantly lower temperatures.
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| 9. |
- Blomquist, Johan, et al.
(författare)
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A Non-Stationary Panel Data Investigation of the Unemployment–Crime Relationship
- 2014
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Ingår i: Social Science Research. - : Elsevier BV. - 0049-089X. ; 44, s. 114-125
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Tidskriftsartikel (refereegranskat)abstract
- Many empirical studies of the economics of crime focus solely on the determinants thereof, and do not consider the dynamic and cross-sectional properties of their data. As a response to this, the current paper offers an in-depth analysis of this issue using data covering 21 Swedish counties from 1975 to 2010. The results suggest that the crimes considered are non-stationary, and that this cannot be attributed to county-specific disparities alone, but that there are also a small number of common stochastic trends to which groups of counties tend to revert. In an attempt to explain these common stochastic trends, we look for a long-run cointegrated relationship between unemployment and crime. Overall, the results do not support cointegration, and suggest that previous findings of a significant unemployment–crime relationship might be spurious.
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| 10. |
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| 11. |
- Blomquist, Johan, et al.
(författare)
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Cod in southern Sweden
- 2021
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Ingår i: Impact of seafood imports on the EU Small-Scale Coastal Fleet. ; , s. 8-14
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 12. |
- Blomquist, Johan, et al.
(författare)
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Do Firm Support Increase Investments? Evidence from the Aquaculture and Fish Processing Sectors in Sweden
- 2022
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Ingår i: Journal of Agricultural and Applied Economics. - : Cambridge University Press (CUP). - 1074-0708 .- 2056-7405. ; 54:2, s. 306-318
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Tidskriftsartikel (refereegranskat)abstract
- The European Union provides firm support to the maritime sector to reach the policy objectives in the Common Fisheries Policy. This paper analyzes to what extent the investment support to aquaculture and fish processing firms in Sweden increases firm investment activity. By doing so, the paper also quantifies the amount of investments that would have been undertaken also without support (deadweight losses, DWL). The results show that the support increases investment in aquaculture with a factor of 0.65, thus with a DWL of 35%. The corresponding number for fish processing is a DWL of 77%.
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| 13. |
- Blomquist, Johan, et al.
(författare)
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Do the CAP subsidies increase employment in Sweden? estimating the effects of government transfers using an exogenous change in the CAP
- 2017
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Ingår i: Regional Science and Urban Economics. - : Elsevier BV. - 0166-0462. ; 63, s. 13-24
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluates the impact of agricultural subsidies (CAP) on employment outside the agricultural sector. A side-effect of the decoupling reform in 2005 was that Sweden introduced a grassland support which caused a redistribution of payments among regions. This heterogeneity in transfers is used to identify the effects of government transfers on regional labour markets. The effect on employment is estimated using Swedish municipality data for the years 2001 to 2009. The subsidy creates private jobs at a cost of about $26,000 per job, which is consistent with earlier estimates based on US data.
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| 14. |
- Blomquist, Johan, et al.
(författare)
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Effekter av stöd till selektiva och rovdjurssäkra redskap
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Bakgrund och frågeställningInom den europeiska fiskeripolitiken finns möjlighet för svenska fiskare att söka stöd för investeringar i selektiva redskap och rovdjursäkra redskap. Syftet med stödet till selektiva redskap är att stimulera investeringar i fiskeredskap som minskar mängden bifångster av oönskade arter och/eller bifångster av fisk och skaldjur som är av oönskad storlek. Stöden till rovdjurssäkra redskap syftar till att stimulera användningen av redskap som skyddar fångster och redskap mot rovdjursangrepp. Denna rapport analyserar i vilket utsträckning stöden har ökat användningen av selektiva och rovdjurssäkra redskap, och om stöden på så sätt har bidragit till att minska mängden oönskad fångst och rovdjursangrepp inom svenskt fiske. För analysen används information om beviljade stöd inom fiskeriprogrammet 2007–2013 (EFF) och havs- och fiskeriprogrammet 2014–2020 (EHFF). Stöd till selektiva redskapTotalt har 60 projekt beviljats investeringsstöd inom selektiva redskap och beviljade offentliga medel för dessa projekt uppgår till totalt 2,1 miljoner kronor. Många av projekten är investeringar i art¬sorterande rist som används inom fisket efter havskräfta och i fisket efter nordhavsräka. Analysen finner att stöden sannolikt har haft en viss positiv effekt på användandet av rist inom kräftfisket, vilket minskat de oönskade fångsterna. Stöden har dock inte ökat användandet av rist inom räkfisket. Analysen visar att stöden till selektiva redskap inom EHFF (fram till juli 2019) är långt ifrån att uppnå målet med att minska oönskade fångster med totalt 2 300 ton fram till år 2023 (samtliga fisken). Analysen finner att förändringar i lagstiftning och regelverk sannolikt har spelat en större roll än stöden när det gäller att skapa incitament att använda selektiva redskap i både kräftfisket och räkfisket.Stöd till rovdjurssäkra redskapInom EHFF kan fiskare söka investeringsstöd för rovdjurssäkra redskap och totalt har 46 projekt beviljats under perioden 2014–2019. Beviljade offentliga medel för dessa 46 projekt uppgår till 4,4 miljoner kronor. Majoriteten av dessa projekt (30 stycken) är investeringar i sälsäkra push-up fällor som främst används i fisket efter lax, öring, och sik i Bottniska viken. Utifrån befintliga data är det svårt att avgöra i vilken mån stödet lett till ökad användning av push-up fällan eftersom de företag som inte fått stöd via EHFF haft möjlighet till nationella stöd från Viltskadefonden för investeringen.Hur kan stödens effektivitet förbättras?Rapporten visar att det är viktigt att handläggare har god kännedom om de investeringar som görs och i vilken mån de kan förväntas bidra till att uppnå målen med fonden. Ett exempel är målet om minskade oönskade fångster där 6 redskapsdetaljer såsom konstruktionen av selektiva redskap påverkar mängden oönskad fångst. Rapporten finner även potentiella målkonflikter mellan resultatindikatorerna inom EHFF. Bränsleeffektivitet och oönskade fångster används båda som indikatorer för stöd till selektiva och rovdjurssäkra redskap medan forskning pekar på sämre bränsleeffektivitet vid mer selektivt fiske. Samverkan och kunskapsutbyte mellan experter och ansvariga handläggare för stöden är därför viktigt.
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| 15. |
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| 16. |
- Blomquist, Johan, et al.
(författare)
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Fiske i fjärran vatten : En studie om EU:s fiskeriavtal med utvecklingsländer
- 2016
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Rapport (refereegranskat)abstract
- Fisheries and fish-related industries comprise an important part of the economic activities in many developing countries. However, many of these countries have limited opportunities to fish outside their coastal zones, since this requires a highly capitalized fleet. A way to utilize national fish resources is to make fisheries agreements whereby foreign fleets pay for the opportunity to fish. For some countries the compensation for fisheries agreements constitutes 30‒50 per cent of the total government budget. In this report the EU’s sustainable partnership agreements with countries in Western Africa, the Pacific and the Indian Ocean are analysed. The purpose is to discuss the positive and negative aspects of the agreements and to identify areas in which the agreements can be improved to contribute better to biological and economic sustainability. (The full text of the report is in Swedish, with an executive summary in English)
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| 17. |
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| 18. |
- Blomquist, Johan, et al.
(författare)
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Fiske i spåren av Covid-19 - en analys av det svenska yrkesfiskets utveckling och tillgång till stöd
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Pandemin med Covid-19 har slagit hårt mot många branscher. För att mildra skadeverkningarna infördes stödåtgärder i flera länder och så även i Sverige. I den här rapporten presenterar vi en genomgång av effekterna av pandemin för svensk fiskenäring. Vi undersöker också vilka stöd näringen har kunnat söka och i vilken mån stöden passar fiskenäringens struktur.Generellt sett hade svenskt yrkesfiske en relativt god ekonomi före pandemin även om variationerna var stora mellan olika regioner och typer av fiske. Covid-19 har troligtvis haft en liten påverkan på svenskt fiske totalt sett om man tittar på perioden från mars 2020 fram till februari 2021. Men det finns skillnader mellan olika arter och vi ser att vissa arter (havskräfta, räkor och gös) påverkas negativt i början av pandemin.Vi ser att majoriteten av fiskeföretagen (74 %) var registrerade som enskild firma år 2019 och näringen har därför framför allt fått stöd som riktar sig till denna typ av företag, exempelvis det så kallade omsättningsstödet. Många företag tappade en stor andel av omsättningen under pandemin, men stora tapp har även skett historiskt av andra orsaker. Att fisket är säsongsbetonat kan ge problem vid stöd som använder referensperioder som ligger under en annan säsong än den som stödet söks för.Förutom de stöd som kunnat sökas generellt av företag i Sverige har fiskeföretag kunnat söka stöd från den Europeiska havs- och fiskerifonden (EHFF) för tillfälligt upphörande av fiskeverksamhet på grund av Covid 19. Dessa stöd har i stor utsträckning beviljats till fartyg på sydkusten och till fartyg som gått ekonomiskt sämre än genomsnittet redan innan Covid-19.
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| 19. |
- Blomquist, Johan, et al.
(författare)
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Fångster av siklöja och priset på löjrom – en ekonomisk analys
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- De senaste åren har Havs- och vattenmyndigheten minskat den mängd siklöja som får fångas i Bottenviken. Minskningen beror på att beståndet av siklöja har minskat. Siklöjan fiskas framförallt för att framställa löjrom. Det innebär att fiskarnas intäkter är starkt beroende av priset på löjrom. Mindre fångster innebär lägre intäkter för fiskarna om inte priset på löjrom samtidigt stiger kraftigt. I denna studie undersöker vi sambandet mellan fångster och priser och finner att priset på löjrom i genomsnitt stiger med mellan 3,7 och 4,6 procent när fångsterna minskar med 10 procent. Priseffekten är stor jämfört med andra svenska fisken och den tycks bli allt större med tiden. Trots detta är den inte tillräckligt stor för att förhindra att minskade fångster leder till lägre intäkter för fisket.
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| 20. |
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| 21. |
- Blomquist, Johan
(författare)
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Förbättrad konkurrenskraft och tillväxt med hjälp av stöd? : effekter av investeringsstöd och startstöd till vattenbruk och beredningsindustri i havs- och fiskeriprogrammet
- 2022
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Rapport (refereegranskat)abstract
- I det svenska havs- och fiskeriprogrammet finns möjlighet för företag att söka stöd för investeringar inom vattenbruk och beredning av fiskprodukter. Syftet med stödet är att främja investeringar som främjar konkurrenskraft, sysselsättning och en hållbar utveckling av sektorerna. Inom vattenbruket ges även startstöd för att underlätta för nya entreprenörer att starta vattenbruksföretag. I denna rapport utvärderas i vilken utsträckning investeringsstöden till vattenbruket och beredningsindustrin har bidragit till att öka konkurrenskraften och tillväxten hos företagen som har fått stöd 2007–2019. Rapporten innehåller även en analys av utvecklingen i vattenbruksföretag som har fått startstöd 2014–2019. För att bedöma företagens konkurrenskraft och tillväxt mäts deras produktivitet, produktionsvärde och sysselsättning. Investeringsstödet har ökat företagens produktionsvärde och sysselsättning Utvärderingen visar att investeringsstödet har bidragit till att stärka tillväxten inom vattenbruket och beredningsindustrin genom ökat produktionsvärde. Inom vattenbruket har investeringsstödet ökat produktionsvärdet med cirka 50 procent jämfört med om inget stöd hade delats ut. Inom beredningsindustrin har investeringsstödet ökat produktionsvärdet med cirka 12 procent jämfört med om inget stöd hade delats ut. Investeringsstödet till vattenbruket har sannolikt ökat sysselsättningen i de vattenbruksföretag som har fått stöd, men effektens storlek är mer osäker än effekten på produktionsvärdet. Utvärderingen visar att stödet har ökat antalet sysselsatta med upp till 1,5 anställda per företag. För företag inom beredningsindustrin som har fått stöd visar utvärderingen inga positiva effekter på sysselsättningen. Utvärderingen visar alltså att investeringsstödet, genom att öka produktionsvärdet, har bidragit positivt till företagens tillväxt. Ökad tillväxt kan i förlängningen främja konkurrenskraften. Däremot finner utvärderingen inga effekter av stöden på företagens produktivitet, varken inom vattenbruket eller beredningsindustrin. Produktivitet är en viktig faktor för långsiktig konkurrenskraft i branscherna. Företag med startstöd har kommit igång med produktionen Utvärderingen visar att vattenbruksföretagen som har fått startstöd har kommit igång med produktionen och ökat antalet anställda. Men utvecklingen ser ut att ha stannat av och legat på en konstant nivå efter år 2016 (till och med år 2019). Det är dock viktigt att poängtera att stödet började beviljas sent under perioden. Därför behövs ekonomiska uppgifter från en längre tidsperiod för att kunna avgöra i vilken mån företagen skapar hållbar tillväxt på sikt. Jämförelse mellan företag med och utan stöd Utvärderingen har analyserat information om företag inom vattenbruk och beredningsindustri med hjälp av statistiska metoder. Både företag som har fått stöd och företag som inte har fått det ingår i analysen. På så vis kan hänsyn tas till hur utvecklingen skulle ha varit om företagen som har fått stöd inte hade fått det (en så kallad kontrafaktisk analys).
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| 22. |
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| 23. |
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| 24. |
- Blomquist, Johan, et al.
(författare)
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Joint management of marine mammals and a fish species: The case of cod and grey seals in the Nordic-Baltic Sea countries
- 2022
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Ingår i: Natural Resource Modeling. - : Wiley. - 0890-8575 .- 1939-7445. ; 35:4
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a simple theoretical, steady-state equilibrium, predator-prey model for the joint management of marine mammals and a fish species. As an empirical case, we choose cod and grey seals in the Nordic-Baltic Sea countries, and several benefits and costs related to the latter are considered. We show that the optimal grey seal population is much lower than the actual population, and this result is robust to variations in relevant parameter values. This result can be explained by the fact that the profit from harvesting cod is much higher than the net benefits from grey seals.
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| 25. |
- Blomquist, Johan
(författare)
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Multiple Inference and Market Integration: An Application to Swedish Fish Markets
- 2015
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Ingår i: Journal of Agricultural Economics. - : Wiley. - 1477-9552 .- 0021-857X. ; 66:1, s. 221-235
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Tidskriftsartikel (refereegranskat)abstract
- This paper, in contrast to earlier studies, tests market integration using a methodology that accounts for the multiplicity problem inherent in testing several time series. This method minimises the risk of finding spurious evidence of market integration. We examine market integration among 12 fish species in Sweden by applying cointegration tests, which identify market integration for two separate clusters of species. Furthermore, we find that the Law of One Price holds for 6 of the 12 species considered.
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| 26. |
- Blomquist, Johan, et al.
(författare)
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Panel bootstrap tests of slope homogeneity
- 2016
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Ingår i: Empirical Economics. - : Springer Science and Business Media LLC. - 0377-7332 .- 1435-8921. ; 50:4, s. 1359-1381
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes two bootstrap-based tests that can be used to infer whether the individual slopes in a panel regression model are homogenous. The first test is suitable when wanting to infer the null of homogeneity versus the general alternative, while the second is suitable when wanting to infer the units of the panel that can be pooled. Both approaches are shown to be asymptotically valid, a property that is verified in small samples using Monte Carlo simulation.
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| 27. |
- Blomquist, Johan, et al.
(författare)
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Price premiums for eco-labelled seafood: effects of the MSC certification suspension in the Baltic Sea cod fishery
- 2019
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Ingår i: European Review of Agricultural Economics. - : Oxford University Press (OUP). - 0165-1587 .- 1464-3618. ; 47:1, s. 50-70
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Tidskriftsartikel (refereegranskat)abstract
- Certification programmes in fisheries have been introduced as a market-based tool for promoting sustainable fishing practices. While consumers appreciate the eco-labels by paying a price premium in the retail market, there is not much research on whether the premium transmits to the fishing industry. This paper adds to the literature by studying price premiums at port for the Swedish Baltic Sea cod fishery that had its Marine Stewardship Council (MSC) certification suspended in 2015. The result shows a price premium of around 11 per cent for small-size cod prior to the suspension of the certification, but no premium for larger cod.
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| 28. |
- Blomquist, Johan, et al.
(författare)
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Price Premiums for Providing Eco-labelled Seafood: Evidence from MSC-certified Cod in Sweden
- 2015
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Ingår i: Journal of Agricultural Economics. - : Wiley. - 0021-857X .- 1477-9552. ; 66, s. 690-704
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Tidskriftsartikel (refereegranskat)abstract
- Eco-labelled seafood is an important tool to promote sustainable development in fisheries. A price premium on eco-labelled seafood signals a return on investment in sustainable fishing methods, providing an incentive for fishers to adopt such methods. This paper investigates whether Swedish fishermen gained a price premium from participating in the Marine Stewardship Council (MSC)-certified Swedish Eastern Baltic cod fishery in the period 2011-2012. Using a detailed dataset of landing tickets and log books, we apply a panel data methodology to estimate the MSC price premium. We cannot find reliable evidence that the consumer level premium for MCS cod is actually passed back to the producers in this case.
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| 29. |
- Blomquist, Johan, et al.
(författare)
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Samhällsekonomiska begrepp i yrkes- och fritidsfiske
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Havs- och vattenmyndigheten har utifrån förvaltningens mål och strategin Framtidens Fiske gett forskarna Johan Blomquist, Lars Persson, Jesper Stage och Staffan Waldo i uppdrag att sammanställa och analysera inom vilka områden och för vilka indikatorer som fritidsfisket och yrkesfisket är jämförbara.Rapporten är en viktig del i det påbörjade arbetet inom den nya framtagna strategin för framtidens fiske och kan kopplas till flera åtgärder inom handlingsplanerna fritidsfiske och fisketurism samt yrkesfiske. I rapporten diskuteras dels vilka indikatorer som alls är meningsfulla att jämföra med motsvarande indikatorer i andra fisken och dels vad som krävs för att åstadkomma jämförbara indikatorer för olika fisken.I rapporten diskuteras även några utvecklingsmöjligheter för framtida datainsamling och framtida analysarbete inom fiskeområdet.
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| 30. |
- Blomquist, Johan, et al.
(författare)
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Scrapping programmes and ITQs : Labour market outcomes and spill-over effects on non-targeted fisheries in Sweden
- 2018
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Ingår i: Marine Policy. - : Elsevier BV. - 0308-597X. ; 88, s. 41-47
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Tidskriftsartikel (refereegranskat)abstract
- Scrapping programmes and individual transferable quotas (ITQs) are two management measures frequently used to reduce overcapacity in fisheries. These measures are often aimed at specific vessel segments targeting specific fish stocks. In this case, fishermen who scrap their vessels or sell their quotas may shift their fishing activities, possibly contributing to overcapacity in other fleets. The aim of this paper is to provide some insights on this issue based on a Swedish scrapping programme for trawlers targeting cod and Norwegian lobster and the introduction of an ITQ system for pelagic vessels introduced in 2008 and 2009. Individual-level data on fishing activities and income from other industries are used to examine how effort and catches have changed after 2009, and to what extent fishermen have left the fishing industry. The lesson learnt from the Swedish case is that fishermen tend to stay in the fishing sector, and this holds true for both participants in the scrapping programme and fishermen who sold their quota in the ITQ system. Therefore measures to reduce overcapacity in targeted fleets have increased fishing pressure and competition for quotas in the Swedish small-scale fleet.
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| 31. |
- Blomquist, Johan, et al.
(författare)
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Seal interactions and exits from fisheries: insights from the Baltic Sea cod fishery
- 2021
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Ingår i: ICES Journal of Marine Science. - : Oxford University Press (OUP). - 1095-9289 .- 1054-3139. ; 78:8, s. 2958-2958
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Tidskriftsartikel (refereegranskat)abstract
- The number of seals in the Baltic Sea has increased dramatically in recent years. While growing seal populations are associated with a thriving marine environment, seals interact with coastal fisheries causing significant damages to catches and gears. One fishery that is severely affected is the coastal cod fishery where the negative impact of seals is believed by many to threaten the existence of the fishery. This article empirically investigates to what extent seal damages can explain the declining number of fishing vessels active in the Baltic Sea coastal cod fishery. The analysis makes use of detailed logbook data and statistical survival models to estimate the effect of seal interactions with fishing gears on the exit probability of vessels in the Swedish cod fishery. The results show that seal interactions is an important factor explaining exits, suggesting that total losses caused by seals go beyond observed costs of broken gears and damaged catches.
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| 32. |
- Blomquist, Johan, et al.
(författare)
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Side-effects of vessel scrapping in Sweden
- 2018
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Ingår i: Policy brief / AgriFood Economics Centre.
-
Annan publikation (populärvet., debatt m.m.)abstract
- In 2008-2009, Sweden implemented a vessel scrapping program for demersal trawlers funded by the European Fisheries Fund (EFF). The purpose was to reduce overcapacity, since the fleet was considered too large. However, funds received from scrapping might be used by fishermen to invest in other fleet segments. We analyze these side-effects of the scrapping program and conclude that: Many fishermen participating in the program did not leave the fishing sector.Part of the scrapping subsidies received was reinvested in new vessels in other fleets. The new vessels target other species, mainly lobster and mackerel.A potential side-effect of scrapping programs is thus generation of overcapacity in other fleets.
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| 33. |
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| 34. |
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| 35. |
- Blomquist, Johan
(författare)
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Testing Homogeneity and Unit Root Restrictions in Panels
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is divided into two distinct parts. The first part contains three chapters, co-authored with Joakim Westerlund, that deal with the analysis of unit root testing, and the second part consists of two chapters on slope homogeneity testing. Chapter 2 continues and extends the analysis in Westerlund (Empirical Economics 37:517–531, 2009), who demonstrates that the performance of the popular LLC (Levin et al., Journal of Econometrics 98:1–24, 2002) panel unit root test depends critically on the choice of lag truncation used when correcting for serial correlation, and that it is only when this parameter is set as a function of time that the power raises above size. The purpose Chapter 2 is to propose a modified test that does not suffer from this drawback. The new test is not only simpler to compute but also superior in terms of small-sample performance, which is illustrated using as an example purchasing power parity for less developed countries. Chapter 3 considers panel unit root testing when there is uncertainty about the deterministic trend. In doing so, it takes PANIC (Bai and Ng, Econometrica 72:1127-1177, 2004), one of the most general and popular panel unit root tests, and demonstrates how it can be modified to determine the extent of both the deterministic trend and non-stationarity of the data. Chapter 4 offers an in-depth analysis of the dynamic and cross-sectional properties of crime using data covering 21 Swedish counties from 1975 to 2010. The results suggest that the crimes considered are non-stationary, and that this cannot be attributed to county-specific disparities alone, but that there are also a small number of common stochastic trends to which groups of counties tend to revert. With this result in mind, we investigate the relationship between unemployment and crime using novel panel cointegration techniques. Overall, the results do not support cointegration, and suggest that previous findings of a significant relationship between unemployment and crime might be spurious. Chapter 5 proposes a test of slope homogeneity for panel data models that is robust to unspecified error serial dependence and heteroscedasticity. The proposed test is an adjusted version of the dispersion-type test suggested by Pesaran and Yamagata (Journal of Econometrics 142, 50–93, 2008) and is shown to have a standard normal distribution, as N, T → ∞. Using Monte Carlo experiments, it is demonstrated that the proposed test performs well in small samples, even when the degree of serial dependence is large. Chapter 6 considers the issue of slope homogeneity testing in panel data models with non-spherical errors. It proposes a bootstrap test of the slope homogeneity hypothesis that is robust to cross-sectional and serial dependence in the errors. The chapter also proposes a bootstrap sequential test that enables differentiation between units with a common slope coefficient vector and units for which the hypothesis of equal slope coefficients fails. Asymptotic properties of the bootstrap tests are derived by letting the time series dimension of the panel increase to infinity, and a small Monte Carlo study is conducted to investigate the small-sample properties.
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| 36. |
- Blomquist, Johan, et al.
(författare)
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Testing slope homogeneity in large panels with serial correlation
- 2013
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Ingår i: Economics Letters. - : Elsevier BV. - 0165-1765. ; 121:3, s. 374-378
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Tidskriftsartikel (refereegranskat)abstract
- Pesaran and Yamagata (Pesaran, M.H., Yamagata, T., Testing slope homogeneity in large panels, Journal of Econometrics 142, 50–93, 2008) propose a test for slope homogeneity in large panels, which has become very popular in the literature. However, the test cannot deal with the practically relevant case of heteroskedastic and/serially correlated errors. The present note proposes a generalized test that accommodates both features.
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| 37. |
- Blomquist, Johan, et al.
(författare)
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Time for Fishing: Bargaining Power in the Swedish Baltic Cod Fishery
- 2015
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Ingår i: Marine Resource Economics. - : University of Chicago Press. - 0738-1360 .- 2334-5985. ; 30:3, s. 315-329
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Tidskriftsartikel (refereegranskat)abstract
- Fishery regulations might not only affect the fleet, but also the relation between fisheries and downstream sectors on the ex-vessel market for fish products. This article estimates the price effects of management reform in the Swedish Baltic Sea cod fishery. In April 2011, as part of a reform process aimed at giving fishers more flexibility, vessels using active gear were given annual non-transferable catch quotas. We examine whether the new management system has altered the bargaining power between fishers and processors in the ex-vessel market for fish. Using a difference-in-differences estimation approach we find that post-reform fishers improve their bargaining power and thus are paid a higher price. However, the price increase is small, amounting to around 2% of the pre-reform price.
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| 38. |
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| 39. |
- Blomquist, Tomas, et al.
(författare)
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From issues to checkpoints and back :
- 2004
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Ingår i: Business Strategy and the Environment. - : Wiley. - 0964-4733 .- 1099-0836. ; 13:6, s. 363-373
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Tidskriftsartikel (refereegranskat)
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| 40. |
- Correia de Verdier, Maria, et al.
(författare)
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Magnetic resonance imaging detected radiation-induced changes in patients with proton radiation-treated arteriovenous malformations
- 2021
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Ingår i: Acta Radiologica Open. - : Sage Publications. - 2058-4601. ; 10:10
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundTreatment of intracranial arteriovenous malformations (AVMs) includes surgery, radiation therapy, endovascular occlusion, or a combination. Proton radiation therapy enables very focused radiation, minimizing dose to the surrounding brain.PurposeTo evaluate the presence of radiation-induced changes on post-treatment MRI in patients with AVMs treated with proton radiation and to compare these with development of symptoms and nidus obliteration.Material and MethodsRetrospective review of pre- and post-treatment digital subtraction angiography and MRI and medical records in 30 patients with AVMs treated with proton radiation. Patients were treated with two or five fractions; total radiation dose was 20–35 physical Gy. Vasogenic edema (minimal, perinidal, or severe), contrast enhancement (minimal or annular), cavitation and nidus obliteration (total, partial, or none) were assessed.Results26 of 30 patients (87%) developed MRI changes. Vasogenic edema was seen in 25 of 30 (83%), abnormal contrast enhancement in 18 of 26 (69%) and cavitation in 5 of 30 (17%). Time from treatment to appearance of MRI changes varied between 5 and 25 months (median 7, mean 10). Seven patients developed new or deteriorating symptoms that required treatment with corticosteroids; all these patients had extensive MRI changes (severe vasogenic edema and annular contrast enhancement). Not all patients with extensive MRI changes developed symptoms. We found no relation between MRI changes and nidus obliteration.ConclusionRadiation-induced MRI changes are seen in a majority of patients after proton radiation treatment of AVMs. Extensive MRI changes are associated with new or deteriorating symptoms.
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| 41. |
- Cunha Goncalves, Doris, et al.
(författare)
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Cardiovascular effects of levosimendan in the early stages of endotoxemia.
- 2007
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Ingår i: Shock. - : Ovid Technologies (Wolters Kluwer Health). - 1073-2322 .- 1540-0514. ; 28:1, s. 71-7
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Tidskriftsartikel (refereegranskat)abstract
- Sepsis-associated myocardial depression is associated with calcium desensitization and adrenergic uncoupling. We conducted a prospective randomized investigation on the effects of the calcium sensitizer, levosimendan, on hemodynamics, myocardial blood flow, and myocardial lactate metabolism during porcine endotoxemia. Twelve pigs were studied. Oxygen consumption was measured by indirect calorimetry, and myocardial blood flow was measured by retrograde thermodilution. Pulmonary, arterial, and venous indwelling catheters allowed measurements of cardiac output, vascular pressures, and blood sampling. Fluids were given at an average of 15 mL . kg . h. After baseline measurements (0 min), an infusion of Escherichia coli LPS (2 microg . kg . min) was started in all animals. Beginning at 100 min, six animals received levosimendan (50 microg . kg . h), whereas six control animals received placebo. The study lasted for 300 min. All animals responded to endotoxin with pulmonary hypertension, a transient decrease in cardiac output, tachycardia, and systemic hypotension. Levosimendan infusion decreased systemic vascular resistance (P = 0.001), coronary vascular resistance (P = 0.004), and mean arterial (P < 0.001) and coronary perfusion pressures (P < 0.001), whereas pulmonary hypertension was unaffected. Heart rate progressively increased in both groups and was significantly higher in the levosimendan group (P = 0.048). Myocardial blood flow remained unchanged in both groups; however, 80 min after the start of levosimendan infusion, left ventricular myocardial hypoxia ensued, as evidenced by a negative myocardial lactate gradient (P = 0.01). Two control and five levosimendan animals died before the end of the study. Early administration of levosimendan during porcine endotoxemia increased heart rate, caused arterial vasodilation, and decreased coronary perfusion pressure, resulting in myocardial hypoxia.
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| 42. |
- Cunha Goncalves, Doris, et al.
(författare)
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Inotropic support during experimental endotoxemic shock : part II. A comparison of levosimendan with dobutamine
- 2009
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Ingår i: Anesthesia and Analgesia. - : Ovid Technologies (Wolters Kluwer Health). - 0003-2999 .- 1526-7598. ; 109:5, s. 1576-83
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We compared the association of levosimendan or dobutamine with norepinephrine for the maintenance of systemic and hepatosplanchnic perfusion during early endotoxemic shock. METHODS: Twenty anesthetized pigs (26.8 +/- 0.5 kg) were instrumented with flow probes and catheters to monitor systemic and regional perfusion as described in our companion article in this issue of the journal. Two animals were excluded because of surgical complications. Oxygen consumption (VO(2)) was measured by indirect calorimetry. Starting 1 h after instrumentation, an endotoxin infusion (Escherichia coli lipopolysaccharide, 2 microg x kg(-1) x h(-1)) was administered for 300 min. Sixty minutes after the start of endotoxin, the animals were fluid resuscitated (20 mL/kg dextran 70); at 120 min, they were randomized into three groups of six animals each: levosimendan (25-50 microg x kg(-1) x h(-1)), dobutamine (10-20 microg x kg(-1) x min(-1)), and control. In the first two groups, norepinephrine (0.5-2 microg x kg(-1) x min(-1)) was added when mean arterial blood pressure (MAP) or= baseline. The data were divided into two subsets: before (0-120 min, all animals) and after (120-300 min, three groups) randomization, and analyzed by analysis of variance. P < 0.05 was considered significant. RESULTS: At 120 min, cardiac output was 15% higher (P < 0.001), systemic vascular resistance was 30% lower (P < 0.001), and MAP decreased 12.5% (P = 0.004); blood flow in the hepatic artery, superior mesenteric artery, and portal vein had increased by 100% (P = 0.004), 60% (P < 0.001), and 20% (P < 0.001), respectively. Between 120 and 300 min, cardiac output and systemic oxygen delivery decreased 50% in control animals (P < 0.05), remained unchanged in the levosimendan group, and increased 60% with dobutamine (P = 0.05). MAP (P = 0.043) and VO(2) (P = 0.001) decreased 20% in the control group. Portal vein flow decreased in the control (50%) and levosimendan (30%) groups (P < 0.001) and was therefore higher in the dobutamine group (P = 0.003) at 300 min. Hepatic and gut oxygen deliveries decreased in the levosimendan (50%, and 30%, respectively, P < 0.001) and control groups (70% and 45%, respectively, P < 0.05); thus, regional oxygen deliveries were greater in the dobutamine group (P < 0.05). In this group, mixed venous and hepatic vein oxygen saturation were maintained; the latter variable was higher than in the other groups (P < 0.05). Although unchanged with dobutamine, arterial (P = 0.020), portal (P = 0.020), and hepatic vein (P = 0.034) lactate concentrations increased twofold with levosimendan. CONCLUSION: In volume-resuscitated endotoxemic pigs, the association of either levosimendan or dobutamine with norepinephrine preserved systemic blood flow, oxygen delivery, and VO(2). However, only dobutamine-norepinephrine maintained portal blood flow, which was associated with preservation of splanchnic and hepatic oxygen homeostasis and stable lactate concentrations.
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| 43. |
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| 44. |
- De Robertis, E, et al.
(författare)
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Elastic properties of the lung and the chest wall in young and adult healthy pigs
- 2001
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Ingår i: European Respiratory Journal. - 1399-3003. ; 17:4, s. 703-711
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding of the elastic pressure/volume (Pel/V) curve is still limited in health and disease. The aim of the present study was to elucidate the Pel/V curve and elastance of the respiratory system (ERS) lung (EL) and chest wall (ECW) in healthy pigs. Six young (20.8 kg) and seven adult (58.9 kg), anaesthetized, paralysed and ventilated pigs were studied. Pel/V curves were recorded at zero end-expiratory pressure (ZEEP) and at positive end-expiratory pressure (PEEP) up to 40 cmH2O with a computer controlled ventilator during an insufflation at a low, constant flow. Pel/V curves of the respiratory system showed a complex pattern in both young and adult pigs. During the insufflation, ERS decreased, increased, fell, and increased again. A second Pel/V curve recorded immediately after the first one showed lower elastance and only one early fall in ERS. ECW fell over the initial segment and was then nearly stable. Difference between 1st and 2nd curves reflected changes in EL caused by recruitment during the 1st insufflation. At PEEP, such signs of collapse and recruitment were reduced. A strong tendency to lung collapse contributes to a complex pattern of elastic pressure/volume curves. At low volumes and distending pressures the chest wall contributes significantly to changes in respiratory system elastance.
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| 45. |
- Elmér, Olle, et al.
(författare)
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Prevention of posttraumatic pulmonary platelet trapping by portacaval transposition
- 1988
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Ingår i: The American Journal of Surgery. - 1879-1883. ; 155:2, s. 289-292
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Tidskriftsartikel (refereegranskat)abstract
- Significant soft-tissue trauma induces platelet activation, aggregation, and sequestration in the lungs. This pulmonary trapping is due either to the size of the platelet aggregates or to changes in the pulmonary microvasculature. To evaluate which one of these mechanisms is responsible for the trapping, we performed portacaval transposition in one group of pigs, making the liver the first receiving capillary bed for blood from the trauma sites in the lower extremities. One week after the operation, the platelets were labeled with indium oxine and reinfused, and the operated animals and a group of six control animals were subjected to standardized soft-tissue trauma to the lower extremities. Sequestration of platelets in the lungs and in the liver was registered dynamically before and for 90 minutes after the trauma. Soft-tissue trauma induced platelet sequestration in the liver in the operated group (p less than 0.01) and in the lungs in the control group (p less than 0.01). Trapping was paralleled by a decrease in the number of circulating platelets. This study has indicated that posttraumatic pulmonary platelet trapping is caused by platelet activation at the trauma sites and not by changes in the pulmonary microvasculature.
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| 46. |
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| 47. |
- Hammarlund, Cecilia, et al.
(författare)
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Hummerfiske på västkusten - mer lönsamt med färre yrkesfiskare?
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Nuvarande förvaltning av det svenska hummerfisket riskerar att leda till överfiske och dålig lönsamhet för yrkesfisket. Kan den samhällsekonomiska nyttan av det yrkesmässiga hummerfisket öka genom att begränsa tillträdet till ett färre antal yrkesfiskare?Vår slutsats är att en sådan åtgärd riskerar att få begränsad effekt på grund av teknisk utveckling i fisket och ett stort intresse för fritidsfiske. Att begränsa antalet yrkesfiskare kan också få negativa ekonomiska konsekvenser för fiskare som inte får tillträde. Vi finner emellertid att en stor del av det yrkesmässiga hummerfisket bedrivs av personer som inte har detta fiske som en huvudsaklig del av sin försörjning.
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| 48. |
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| 49. |
- Hammarlund, Cecilia, et al.
(författare)
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Intäkter för svenska kräftfiskare på västkusten
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Havskräfta är en viktig art för svenskt fiske. Kräftan fångas antingen med bur eller med trål i Kattegatt och Skagerrak. På uppdrag av Havs- och vattenmyndigheten analyseras yrkesfiskets intäkter och fartygens landningsmönster för att ge underlag till en bedömning av effekterna av att minska utrymmet för trålfiske och öka utrymmet för burfiske.Analysen visar att trålfisket generellt sett är mindre beroende av havskräfta än burfisket, men att det finns ett antal fiskare, framför allt de med mindre trålfartyg, som får stora delar av sina intäkter från de aktuella områdena. Förändrade områden för fisket påverkar inte bara fördelningen mellan trål- och burfiske, utan kan också förändra var landningarna av havskräfta sker. Vissa landningshamnar har idag stora landningar av trålfiskad kräfta men endast marginella landningar av burfångad.
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| 50. |
- Hammarlund, Cecilia, et al.
(författare)
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Local markets and price premiums—The case of the establishment of the Stockholm fish auction
- 2021
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Ingår i: Fisheries Research. - : Elsevier BV. - 0165-7836 .- 1872-6763. ; 236
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Tidskriftsartikel (refereegranskat)abstract
- The promotion of locally produced food has been a growing marketing trend in recent years. Locally produced food is associated with positive values such as environmental benefits, fresher and safer products as well as contributing to building closer ties between people in local communities. We use a case study were a local fish auction was established in the Stockholm area in Sweden with the aim to supply the local market with fish, mainly pikeperch, from the region. Using monthly prices we investigate if the establishment of the auction has resulted in a price premium and separate markets for locally caught pikeperch. Our results show that there is no price premium and that the Stockholm market is not decoupled from the national market after the establishment of the new auction. In fact, the Swedish market appears to become more integrated and non-auction buyers of pikeperch have to pay more to fishers after the establishment of the auction.
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