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result(s) for
"Andersson, Helén"
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Proangiogenic effects of environmentally relevant levels of bisphenol A in human primary endothelial cells
by
Andersson, Helén
,
Brittebo, Eva
in
angiogenesis
,
Benzhydryl Compounds
,
Biomedical and Life Sciences
2012
Bisphenol A (BPA) is widely used in the manufacturing of consumer products such as plastic food containers and food cans. Experimental studies suggest a relationship between exposure to BPA and changes in metabolic processes and reproductive organs. Also, epidemiological studies report an association between elevated exposure to BPA and cardiovascular disease and diabetes. Although alterations in the vascular endothelium are implicated in pathological conditions associated with BPA, little is known about the effects of BPA in the human endothelium. This study aimed to investigate the effects of 0.1 nM–1 μM of BPA on selected biomarkers of endothelial dysfunction, inflammation, and angiogenesis in human umbilical vein endothelial cells (HUVEC). The mRNA expression of biomarkers was assayed using qRT-PCR, and the production of nitric oxide and reactive oxygen species was measured using the H
2
DCFDA and the DAF-FM assays. The effect of BPA on phosphorylated eNOS was examined using Western blot and immunofluorescence, and the endothelial tube formation assay was used to investigate in vitro angiogenesis. BPA (≤1 μM) increased the mRNA expression of the proangiogenic genes VEGFR-2, VEGF-A, eNOS, and Cx43 and increased the production of nitric oxide in HUVEC. Furthermore, BPA increased the expression of phosphorylated eNOS and endothelial tube formation in HUVEC. These studies demonstrate that environmentally relevant levels of BPA have direct proangiogenic effects on human primary endothelial cells in vitro suggesting that the human endothelium may be an important target for BPA.
Journal Article
High climate velocity and population fragmentation may constrain climate-driven range shift of the key habitat former Fucus vesiculosus
by
Herkül, Kristjan
,
Sandman, Antonia Nyström
,
Jonsson, Per R.
in
Anthropogenic factors
,
Assisted migration
,
atmosphere model
2018
Aim: The Baltic Sea forms a unique regional sea with its salinity gradient ranging from marine to nearly freshwater conditions. It is one of the most environmentally impacted brackish seas worldwide, and the low biodiversity makes it particularly sensitive to anthropogenic pressures including climate change. We applied a novel combination of models to predict the fate of one of the dominant foundation species in the Baltic Sea, the bladder wrack Fucus vesiculosus. Location: The Baltic Sea. Methods: We used a species distribution model to predict climate change-induced displacement of F. vesiculosus and combined these projections with a biophysical model of dispersal and connectivity to explore whether the dispersal rate of locally adapted genotypes may match estimated climate velocities to recolonize the receding salinity gradient. In addition, we used a population dynamic model to assess possible effects of habitat fragmentation. Results: The species distribution model showed that the habitat of F. vesiculosus is expected to dramatically shrink, mainly caused by the predicted reduction of salinity. In addition, the dispersal rate of locally adapted genotypes may not keep pace with estimated climate velocities rendering the recolonization of the receding salinity gradient more difficult. A simplistic model of population dynamics also indicated that the risk of local extinction may increase due to future habitat fragmentation. Main conclusions: Results point to a significant risk of locally adapted genotypes being unable to shift their ranges sufficiently fast considering the restricted dispersal and long generation time. The worst scenario is that F. vesiculosus may disappear from large parts of the Baltic Sea before the end of this century with large effects on the biodiversity and ecosystem functioning. We finally discuss how to reduce this risk through conservation actions, including assisted colonization and assisted evolution.
Journal Article
Combined climate change and nutrient load impacts on future habitats and eutrophication indicators in a eutrophic coastal sea
2020
Eutrophication and climate change will affect habitats of species and more generally, the structure and functioning of ecosystems. We used a three-dimensional, coupled hydrodynamic-biogeochemical model to investigate potential future changes in size and location of potential habitats of marine species during the 21st century in a large, eutrophicated brackish sea (the Baltic Sea, northern Europe). We conducted scenario projections under the combined impact of nutrient load and climate change. Possible future changes of the eutrophication state of this sea were also assessed through two policy-relevant indicators. The results imply a physiologically more stressful environment for marine species by the end of the 21st century: volumes of higher salinity water become more hypoxic/anoxic and the volumes of low salinity, oxic water increase. For example, these results impact and reduce cod reproductive habitats. The decrease is mainly climate change induced in the Baltic basins less directly influenced by inflows of saline, oxic water to the Baltic Sea (E Gotland and Gdansk Basins). In basins more directly influenced by such inflows (Arkona and Bornholm Basins), the combined effect from climate change and nutrient loads is of importance. The results for the eutrophication state indicators clearly indicate a more eutrophic sea than at present without a rigorous nutrient reduction policy, that is, the necessity to implement the Baltic Sea Action Plan. The multidisciplinary, multiscenario assessment strategy presented here provides a useful concept for the evaluation of impacts from cumulative stresses of changing climate and socioeconomic pressures on future eutrophication indicators and habitats of marine species.
Journal Article
Impact of Climate Change on Ecological Quality Indicators and Biogeochemical Fluxes in the Baltic Sea: A Multi-Model Ensemble Study
by
Meier, H. E. Markus
,
Hordoir, Robinson
,
Müller-Karulis, Bärbel
in
Anoxic waters
,
Atmospheric Sciences
,
Baltic Sea
2012
Multi-model ensemble simulations using three coupled physical–biogeochemical models were performed to calculate the combined impact of projected future climate change and plausible nutrient load changes on biogeochemical cycles in the Baltic Sea. Climate projections for 1961–2099 were combined with four nutrient load scenarios ranging from a pessimistic business-as-usual to a more optimistic case following the Helsinki Commission′s (HELCOM) Baltic Sea Action Plan (BSAP). The model results suggest that in a future climate, water quality, characterized by ecological quality indicators like winter nutrient, summer bottom oxygen, and annual mean phytoplankton concentrations as well as annual mean Secchi depth (water transparency), will be deteriorated compared to present conditions. In case of nutrient load reductions required by the BSAP, water quality is only slightly improved. Based on the analysis of biogeochemical fluxes, we find that in warmer and more anoxic waters, internal feedbacks could be reinforced. Increased phosphorus fluxes out of the sediments, reduced denitrification efficiency and increased nitrogen fixation may partly counteract nutrient load abatement strategies.
Journal Article
Baltic Sea ecosystem response to various nutrient load scenarios in present and future climates
by
Robinson Hordoir
,
Eilola, Kari
,
Markus Meier, H E
in
Biogeochemistry
,
Climate change
,
Climate effects
2019
The Baltic Sea is a shallow, semi-enclosed brackish sea suffering like many other coastal seas from eutrophication caused by human impact. Hence, nutrient load abatement strategies are intensively discussed. With the help of a high-resolution, coupled physical-biogeochemical circulation model we investigate the combined impact of changing nutrient loads from land and changing climate during the 21st century as projected from a global climate model regionalized to the Baltic Sea region. Novel compared to previous studies are an extraordinary spin-up based upon historical reconstructions of atmospheric, nutrient load and runoff forcing, revised nutrient load scenarios and a comparison of nutrient load scenario simulations with and without changing climate. We found in almost all scenario simulations, with differing nutrient inputs, reduced eutrophication and improved ecological state compared to the reference period 1976–2005. This result is a long-lasting consequence of ongoing nutrient load reductions since the 1980s. Only in case of combined high-end nutrient load and climate scenarios, eutrophication is reinforced. Differences compared to earlier studies are explained by the experimental setup including nutrient loads during the historical period and by the projected nutrient loads. We found that the impact of warming climate may amplify the effects of eutrophication and primary production. However, effects of changing climate, within the range of considered greenhouse gas emission scenarios, are smaller than effects of considered nutrient load changes, in particular under low nutrient conditions. Hence, nutrient load reductions following the Baltic Sea Action Plan will lead to improved environmental conditions independently of future climate change.
Journal Article
Long-term progression and drivers of coastal zoobenthos in a changing system
2015
Coastal zones are facing climate-driven change coupled with escalating eutrophication. With increasing shifts in hydrographic conditions during the past few decades, a focal task is to understand how environmental drivers affect zoobenthic communities, which play a crucial role in ecosystem functioning. By using long-term data, spanning 40 yr (1973 to 2013) in the northern Baltic Sea, we showed a disparity in zoobenthic responses with pronounced changes in community composition and a trend towards decreased biomass in sheltered areas, while biomasses increased in exposed areas of the coastal zone. We used generalized additive modeling to show that bottom oxygen saturation, sea surface temperature and organic load of the sediments were the main environmental drivers behind contrasting patterns in biomass progression. Oxygen saturation alone explained over one third of the deviation in the biomass developments in sheltered areas, while exposed areas were mainly limited by organic content of the sediments. We analyzed high-resolution climate-scenario simulations, following the Intergovernmental Panel on Climate Change scenarios for the Baltic Sea region in combination with different nutrient load scenarios, for the end of the 21st century. The scenario outcomes showed negative trends in bottom oxygen concentrations throughout the coastal and archipelago zone along with overall increasing temperatures and primary production, and decreasing salinity. Our results suggest that these projected future conditions will strengthen the observed pattern in decreasing zoobenthic production in the immediate coastal zones. Moreover, the potential intensification of unfavorable conditions expanding seaward may lead to an expansion of biomass loss to more exposed sites.
Journal Article
Has eutrophication promoted forage fish production in the Baltic Sea?
by
MacKenzie, Brian R.
,
Eero, Margit
,
Almroth-Rosell, Elin
in
Animals
,
Anthropogenic factors
,
Anthropology
2016
Reducing anthropogenic nutrient inputs is a major policy goal for restoring good environmental status of coastal marine ecosystems. However, it is unclear to what extent reducing nutrients would also lower fish production and fisheries yields. Empirical examples of changes in nutrient loads and concurrent fish production can provide useful insights to this question. In this paper, we investigate to what extent a multi-fold increase in nutrient loads from the 1950s to 1980s enhanced forage fish production in the Baltic Sea. We use monitoring data on fish stock dynamics covering the period of the nutrient increase, combined with nutrient concentrations from a 3-dimensional coupled physical-biogeochemical ocean model. The results suggest that nutrient enrichment enhanced the biomass level of forage fish by up to 50 % in some years and areas due to increased body weight of fish. However, the trends in fish biomasses were generally decoupled from changes in nutrient concentrations.
Journal Article
The cost-effectiveness of a two-step blood pressure screening programme in a dental health-care setting
by
Svensson, Mikael
,
Andersson, Helen
,
Bergh, Håkan
in
Analysis
,
Blood pressure
,
Cardiology and Cardiovascular Disease
2021
Hypertension is one of the largest contributors to the disease burden and a major economic challenge for health-care systems. Early detection of persons with high blood pressure can be achieved through screening and has the potential to reduce morbidity and mortality. We evaluate the cost-effectiveness of an opportunistic hypertension screening programme in a dental-care facility for individuals aged 40-75 in comparison to care as usual (the no-screening baseline scenario). A cost-effectiveness analysis (CEA) was carried out from the payer and societal perspectives, and the short-term (from screening until diagnosis has been established) cost per identified case of hypertension and long-term (20 years) cost per quality-adjusted life year (QALY) were reported. Data on the short-term cost were based on a real-world screening programme in which 2025 healthy individuals were screened for hypertension. Data on the long-term cost were based on the short-term outcomes combined with modelling in a Markov cohort model. Deterministic and probabilistic sensitivity analyses were carried out to assess uncertainty. The short-term analysis showed an additional cost of 4,800 SEK ([euro]470) per identified case of hypertension from the payer perspective and from the societal perspective 12,800 SEK ([euro]1,240). The long-term analysis showed a payer cost per QALY of 2.2 million SEK ([euro]210,000) and from the societal perspective 2.8 million SEK per QALY ([euro]270,000). The long-term model results showed that the screening model is unlikely to be cost-effective in a country with a well-developed health-care system and a relatively low prevalence of hypertension.
Journal Article
Extreme sea levels in the Baltic Sea under climate change scenarios – Part 1: Model validation and sensitivity
by
Arneborg, Lars
,
Dieterich, Christian
,
Gröger, Matthias
in
Atmospheric circulation
,
Atmospheric forcing
,
Atmospheric models
2019
We analyze extreme sea levels (ESLs) and related uncertainty in an ensemble of regional climate change scenarios for the Baltic Sea. The ERA-40 reanalysis and five Coupled Model Intercomparison Project phase 5 (CMIP5) global general circulation models (GCMs) have been dynamically downscaled with the coupled atmosphere–ice–ocean model RCA4-NEMO (Rossby Centre regional atmospheric model version 4 – Nucleus for European Modelling of the Ocean). The 100-year return levels along the Swedish coast in the ERA-40 hindcast are within the 95 % confidence limits of the observational estimates, except those on the west coast. The ensemble mean of the 100-year return levels averaged over the five GCMs shows biases of less than 10 cm. A series of sensitivity studies explores how the choice of different parameterizations, open boundary conditions and atmospheric forcing affects the estimates of 100-year return levels. A small ensemble of different regional climate models (RCMs) forced with ERA-40 shows the highest uncertainty in ESLs in the southwestern Baltic Sea and in the northeastern part of the Bothnian Bay. Some regions like the Skagerrak, Gulf of Finland and Gulf of Riga are sensitive to the choice of the RCM. A second ensemble of one RCM forced with different GCMs uncovers a lower sensitivity of ESLs against the variance introduced by different GCMs. The uncertainty in the estimates of 100-year return levels introduced by GCMs ranges from 20 to 40 cm at different stations and includes the estimates based on observations. It is of similar size to the 95 % confidence limits of 100-year return levels from tide gauge records.
Journal Article
Comparing reconstructed past variations and future projections of the Baltic Sea ecosystem-first results from multi-model ensemble simulations
by
Weslawski, Jan-Marcin
,
Müller-Karulis, Bärbel
,
Schimanke, Semjon
in
92.05.Df
,
92.70.Er
,
92.70.Kb
2012
Multi-model ensemble simulations for the marine biogeochemistry and food web of the Baltic Sea were performed for the period 1850-2098, and projected changes in the future climate were compared with the past climate environment. For the past period 1850-2006, atmospheric, hydrological and nutrient forcings were reconstructed, based on historical measurements. For the future period 1961-2098, scenario simulations were driven by regionalized global general circulation model (GCM) data and forced by various future greenhouse gas emission and air- and riverborne nutrient load scenarios (ranging from a pessimistic 'business-as-usual' to the most optimistic case). To estimate uncertainties, different models for the various parts of the Earth system were applied. Assuming the IPCC greenhouse gas emission scenarios A1B or A2, we found that water temperatures at the end of this century may be higher and salinities and oxygen concentrations may be lower than ever measured since 1850. There is also a tendency of increased eutrophication in the future, depending on the nutrient load scenario. Although cod biomass is mainly controlled by fishing mortality, climate change together with eutrophication may result in a biomass decline during the latter part of this century, even when combined with lower fishing pressure. Despite considerable shortcomings of state-of-the-art models, this study suggests that the future Baltic Sea ecosystem may unprecedentedly change compared to the past 150 yr. As stakeholders today pay only little attention to adaptation and mitigation strategies, more information is needed to raise public awareness of the possible impacts of climate change on marine ecosystems.
Journal Article