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Sökning: WFRF:(Wikner Johan) > (2015-2019)

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1.
  • Ahlgren, Joakim, et al. (författare)
  • Orsaker till minskande syrehalter i Bottenhavet
  • 2017
  • Rapport (refereegranskat)abstract
    • Resultat från den nationella miljöövervakningen visar att syrehalterna i Bottenhavet har minskat sedan 1970-talet, en minskning som accelererat från 1990. För att ha möjlighet att på något sätt kunna åtgärda denna försämring av den marina miljön är det nödvändigt att identifiera orsakerna till denna syreminskning, eftersom olika orsaker kan kräva olika former av åtgärder. Om orsaken till exempel är ökad syreförbrukning beroende på regional övergödning, skulle detta innebära ökat behov av regionala reningsåtgärder. Målsättningen med projektet var därmed att ge en tillförlitlig förklaring till de sjunkande syrehalterna i Bottenhavet under de senaste 20 åren genom att använda data från de nationella miljöövervakningsprogrammen. De huvudhypoteser som undersöktes som orsaker till de sjunkande syrehalterna var:  • Ökad regional gödning av Bottenhavet och därmed ökad produktion.  • Tillförsel av syrefattigt och fosfatrikt från Egentliga Östersjön.  • Starkare haloklin och försämrad ventilation av Bottenhavets djupvatten.  • Ökad temperatur och ökad tillförsel av löst organiskt kol. Analys av tidsserier och modellanalyser utifrån miljöövervaknings- och forskningsdata visade att den observerade syrehaltsminskningen i Bottenhavets djupvatten främst beror på en ökning av vattentemperaturen och delvis på en ökning av löst organiskt kol i vattnet, samt tillflöde från Egentliga Östersjön. Dataanalysen visade däremot inget tydligt stöd för att ökad produktion av biomassa i Bottenhavet orsakat de minskande syrehalterna. Detta gäller indikatorer för växtplankton, sedimentation och bakterieplankton som alla förväntas öka vid ökad produktion och det finns således inga direkta indicier för att stödja hypotesen om ökad gödning av Bottenhavet.  Sammantaget visar de analyser som gjorts inom projektet att Bottenhavets framtida hälsa främst gynnas av en kombination av åtgärder för att motverka globala klimatförändringar, samt åtgärder för att förbättra vattenkvaliteten i Egentliga Östersjön. Näringstillförsel från Bottenhavets avrinningsområden bedöms främst ha haft betydelse för syresituationen i kustnära vattenförekomster. Den bedöms därför inte i betydande omfattning ha orsakat de minskande syrehalterna i Bottenhavets utsjöområden.  
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2.
  • Ahlgren, Joakim, et al. (författare)
  • Temperature, DOC level and basin interactions explain the declining oxygen concentrations in the Bothnian Sea
  • 2017
  • Ingår i: Journal of Marine Systems. - : Elsevier BV. - 0924-7963 .- 1879-1573. ; 170, s. 22-30
  • Tidskriftsartikel (refereegranskat)abstract
    • Hypoxia and oxygen deficient zones are expanding worldwide. To properly manage this deterioration of the marine environment, it is important to identify the causes of oxygen declines and the influence of anthropogenic activities. Here, we provide a study aiming to explain the declining oxygen levels in the deep waters of the Bothnian Sea over the past 20 years by investigating data from environmental monitoring programmes. The observed decline in oxygen concentrations in deep waters was found to be primarily a consequence of water temperature increase and partly caused by an increase in dissolved organic carbon (DOC) in the seawater (R-Adj(2). = 0.83) as well as inflow from the adjacent sea basin. As none of the tested eutrophication-related predictors were significant according to a stepwise multiple regression, a regional increase in nutrient inputs to the area is unlikely to explain a significant portion of the oxygen decline. Based on the findings of this study, preventing the development of anoxia in the deep water of the Bothnian Sea is dependent on the large-scale measures taken to reduce climate change. In addition, the reduction of the nutrient load to the Baltic Proper is required to counteract the development of hypoxic and phosphate-rich water in the Baltic Proper, which can form deep water in the Bothnian Sea. The relative importance of these sources to oxygen consumption is difficult to determine from the available data, but the results clearly demonstrate the importance of climate related factors such as temperature, DOC and inflow from adjacent basins for the oxygen status of the sea.
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4.
  • Andersson, Agneta, et al. (författare)
  • Projected future climate change and Baltic Sea ecosystem management
  • 2015
  • Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 44:Supplement 3, s. S345-S356
  • Tidskriftsartikel (refereegranskat)abstract
    • Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 degrees C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase similar to 30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes.
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5.
  • Arnaud, Laurent, et al. (författare)
  • Effect of Corticosteroids and Cyclophosphamide on Sex Hormone Profiles in Male Patients With Systemic Lupus Erythematosus or Systemic Sclerosis
  • 2017
  • Ingår i: Arthritis & Rheumatology. - : WILEY. - 2326-5191 .- 2326-5205. ; 69:6, s. 1272-1279
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective: Systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) are autoimmune diseases that predominantly affect female patients, and therefore fewer investigations have been conducted in men. The aim of this study was to analyze sex hormone levels in male patients with SLE and those with SSc, compared to matched controls, in relation to the use of corticosteroids and cyclophosphamide (CYC).Methods: Sex hormone levels were measured in fasting blood samples from male patients with SLE (n=71) and those with SSc (n=29) and compared to population-based, age-matched male controls. Relevant hormone profiles were identified using cluster analysis.Results: Male SLE patients had higher levels of luteinizing hormone (LH) (P<0.0001) and more frequent bioactive testosterone deficiency (P=0.02) than their matched controls. The current dosage of prednisolone correlated inversely with the levels of bioactive testosterone (r=-0.36, P=0.03). Cluster analysis identified a subset of SLE patients with increased levels of follicle-stimulating hormone, LH, and prolactin as well as lower levels of bioactive testosterone (P<0.0001) in relation to higher daily doses of prednisolone. In male SSc patients, levels of testosterone (P=0.03) and bioactive testosterone (P=0.02) were significantly lower than those in matched controls. Use of CYC during the previous year was associated with lower bioactive testosterone levels in both SLE patients (P=0.02) and SSc patients (P=0.01), after adjustment for age.Conclusion: The results of this study highlight the negative impact of corticosteroids on gonadal function in men with SLE. Furthermore, use of CYC during the year prior to study inclusion impaired bioactive testosterone levels in male patients with either SLE or SSc. Physicians should be more aware of the possibility of hypogonadism in male patients with autoimmune diseases. The need for hormonal supplementation remains to be formally evaluated in these patients.
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6.
  • Båmstedt, Ulf, 1946-, et al. (författare)
  • Mixing depth and allochthonous dissolved organic carbon: controlling factors of coastal trophic balance
  • 2016
  • Ingår i: Marine Ecology Progress Series. - Oldendorf/Luhe : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 561, s. 17-29
  • Tidskriftsartikel (refereegranskat)abstract
    • ABSTRACT: The interacting effects of different mixing depths and increased allochthonous dissolved organic carbon (DOC) on the ratio of heterotrophic to autotrophic production (i.e. trophic balance) was evaluated in a mesocosm study with a stratified water column. An autumn plankton community from the northern Bothnian Sea showed significantly decreased phytoplankton production and somewhat increased bacterial production with added DOC. In addition, increased mixing depth further reduced phytoplankton production. With a deep pycnocline and added DOC, the system became net-heterotrophic, with an average bacteria-to-phytoplankton production ratio of 1.24. With a deep pycnocline without added DOC, the trophic balance was changed to 0.44 (i.e. autotrophic). With a shallow pycnocline, the system remained net-autotrophic irrespective of DOC addition. We propose that increased precipitation in northern Europe due to climate change may result in changed density stratification and increased allochthonous DOC transport to the sea, leading to more heterotrophic coastal aquatic ecosystems. Such a scenario may entail reduced biological production at higher trophic levels and enhanced CO2 emission to the atmosphere.
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7.
  • Huseby, Siv, et al. (författare)
  • Bacterioplankton growth
  • 2018
  • Rapport (övrigt vetenskapligt/konstnärligt)abstract
    • Bacterioplankton growth rate is an indicator of the decomposition of organic matter and thereby trophic status of the Sea. The bacterioplankton metabolism accounts for about half of the mineralization of organic matter and thereby pelagic oxygen consumption.The bacterioplankton growth rate in deep waters indicates good trophic status in the off-shore Bothnian Bay and Bothnian Sea. Deep water growth rates were 67 % higher than at corresponding depths in the Atlantic Ocean, lacking excess enrichment. The decline that has earlier been reported has now ceased. During the last few years the growth rates has increased some and there is now no significant trends in any of the studied basins.
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8.
  • Kifle, Yonatan Habteslassie, et al. (författare)
  • NFC Powered Implantable Temperature Sensor
  • 2019
  • Ingår i: 2019 41ST ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC). - : IEEE. - 9781538613115 - 9781538613122 ; , s. 4359-4362
  • Konferensbidrag (refereegranskat)abstract
    • Inductively powered 99% accurate implantable temperature sensor is designed, characterized and the findings are presented in this paper. The implantable sensors deliver a continuous temperature reading to external storage or readout devices via Near Field Communication interface. A 2.76 mu H rectangular inductive coil printed on a thin biocompatible plastic substrate is designed to establish the coupling link through NFC interface with external readout devices. A commercially available wide range temperature sensor chip is mounted along with the developed inductive coil on the same plastic substrate. For 50 samples, the received signal strength indicator, temperature accuracy and statistical distribution of measurement levels is investigated. Comparison of predetermined temperature in a controlled temperature and humidity chamber versus the temperature reading from the developed sensors proves a 99% accuracy.
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9.
  • Morf, Andrea, 1968, et al. (författare)
  • Remissyttrande: Sveriges nationella havsplaner 2018
  • 2018
  • Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
    • Havsmiljöinstitutet lämnar härmed synpunkter på dokumenten Förslag till Havsplan, Miljökonsekvensbeskrivning (MKB) samt Hållbarhetsbedömning (HB) för havsplanområdena Bottenviken, Östersjön och Västerhavet, utarbetade av Havs- och Vattenmyndigheten (HaV). Havsmiljöinstitutets (och ingående universitets) experter har tolkat sin uppgift bredare än att svara på remissfrågorna om planernas innehåll och kunskapsbas. Institutet kommenterar ur ett brett tvärvetenskapligt perspektiv följande: 1. rollen som akademin och institutet har spelat i havsplaneringen hittills, 2. kust- och havsplanerings¬systemet och processen, samt 3. dokumenten och kunskapsbasen. Här ingår förslag hur allt kunde utvecklas vidare, inklusive Institutets egen roll som länk mellan forskning och förvaltning, både på kortare och längre sikt.
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10.
  • Muelbert, Jose H., et al. (författare)
  • ILTER : The International Long-Term Ecological Research Network as a Platform for Global Coastal and Ocean Observation
  • 2019
  • Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 6
  • Forskningsöversikt (refereegranskat)abstract
    • Understanding the threats to global biodiversity and ecosystem services posed by human impacts on coastal and marine environments requires the establishment and maintenance of ecological observatories that integrate the biological, physical, geological, and biogeochemical aspects of ecosystems. This is crucial to provide scientists and stakeholders with the support and knowledge necessary to quantify environmental change and its impact on the sustainable use of the seas and coasts. In this paper, we explore the potential for the coastal and marine components of the International Long-Term Ecological Research Network (ILTER) to fill this need for integrated global observation, and highlight how ecological observations are necessary to address the challenges posed by climate change and evolving human needs and stressors within the coastal zone. The ILTER is a global network encompassing 44 countries and 700 research sites in a variety of ecosystems across the planet, more than 100 of which are located in coastal and marine environments (ILTER-CMS). While most of the ILTER-CMS were established after the year 2000, in some cases they date back to the early 1900s. At ILTER sites, a broad variety of abiotic and biotic variables are measured, which may feed into other global initiatives. The ILTER community has produced tools to harmonize and compare measurements and methods, allowing for data integration workflows and analyses between and within individual ILTER sites. After a brief historical overview of ILTER, with emphasis on the marine component, we analyze the potential contribution of the ILTER-CMS to global coastal and ocean observation, adopting the "Strength, Weakness, Opportunity and Threats (SWOT)" approach. We also identify ways in which the in situ parameters collected at ILTER sites currently fit within the Essential Ocean Variables framework (as proposed by the Framework for Ocean Observation recommendations) and provide insights on the use of new technology in long-term studies. Final recommendations point at the need to further develop observational activities at LTER sites and improve coordination among them and with external related initiatives in order to maximize their exploitation and address present and future challenges in ocean observations.
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