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| 2. |
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| 3. |
- Langner, J., et al.
(författare)
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A multi-model study of impacts of climate change on surface ozone in Europe
- 2012
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 12:21, s. 10423-10440
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Tidskriftsartikel (refereegranskat)abstract
- The impact of climate change on surface ozone over Europe was studied using four offline regional chemistry transport models (CTMs) and one online regional integrated climate-chemistry model (CCM), driven by the same global projection of future climate under the SRES A1B scenario. Anthropogenic emissions of ozone precursors from RCP4.5 for year 2000 were used for simulations of both present and future periods in order to isolate the impact of climate change and to assess the robustness of the results across the different models. The sensitivity of the simulated surface ozone to changes in climate between the periods 20002009 and 2040-2049 differs by a factor of two between the models, but the general pattern of change with an increase in southern Europe is similar across different models. Emissions of isoprene differ substantially between different CTMs ranging from 1.6 to 8.0 Tg yr(-1) for the current climate, partly due to differences in horizontal resolution of meteorological input data. Also the simulated change in total isoprene emissions varies substantially across models explaining part of the different climate response on surface ozone. Ensemble mean changes in summer mean ozone and mean of daily maximum ozone are close to 1 ppb(v) in parts of the land area in southern Europe. Corresponding changes of 95-percentiles of hourly ozone are close to 2 ppb(v) in the same region. In northern Europe ensemble mean for mean and daily maximum show negative changes while there are no negative changes for the higher percentiles indicating that climate impacts on O-3 could be especially important in connection with extreme summer events.
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| 4. |
- Otero, Noelia, et al.
(författare)
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A multi-model comparison of meteorological drivers of surface ozone over Europe
- 2018
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 18:16, s. 12269-12288
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Tidskriftsartikel (refereegranskat)abstract
- The implementation of European emission abatement strategies has led to a significant reduction in the emissions of ozone precursors during the last decade. Ground-level ozone is also influenced by meteorological factors such as temperature, which exhibit interannual variability and are expected to change in the future. The impacts of climate change on air quality are usually investigated through air-quality models that simulate interactions between emissions, meteorology and chemistry. Within a multi-model assessment, this study aims to better understand how air-quality models represent the relationship between meteorological variables and surface ozone concentrations over Europe. A multiple linear regression (MLR) approach is applied to observed and modelled time series across 10 European regions in springtime and summertime for the period of 2000-2010 for both models and observations. Overall, the air-quality models are in better agreement with observations in summertime than in springtime and particularly in certain regions, such as France, central Europe or eastern Europe, where local meteorological variables show a strong influence on surface ozone concentrations. Larger discrepancies are found for the southern regions, such as the Balkans, the Iberian Peninsula and the Mediterranean basin, especially in springtime. We show that the air-quality models do not properly reproduce the sensitivity of surface ozone to some of the main meteorological drivers, such as maximum temperature, relative humidity and surface solar radiation. Specifically, all air-quality models show more limitations in capturing the strength of the ozone-relative-humidity relationship detected in the observed time series in most of the regions, for both seasons. Here, we speculate that dry-deposition schemes in the air-quality models might play an essential role in capturing this relationship. We further quantify the relationship between ozone and maximum temperature (m(o3-T), climate penalty) in observations and air-quality models. In summertime, most of the air-quality models are able to reproduce the observed climate penalty reasonably well in certain regions such as France, central Europe and northern Italy. However, larger discrepancies are found in springtime, where air-quality models tend to overestimate the magnitude of the observed climate penalty.
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| 5. |
- Simpson, David, 1961, et al.
(författare)
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Impacts of climate and emission changes on nitrogen deposition in Europe: a multi-model study
- 2014
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 14:13, s. 6995-7017
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Tidskriftsartikel (refereegranskat)abstract
- The impact of climate and emissions changes on the deposition of reactive nitrogen (Nr) over Europe was studied using four offline regional chemistry transport models (CTMs) driven by the same global projection of future climate over the period 2000-2050. Anthropogenic emissions for the years 2005 and 2050 were used for simulations of both present and future periods in order to isolate the impact of climate change, hemispheric boundary conditions and emissions, and to assess the robustness of the results across the different models. The results from these four CTMs clearly show that the main driver of future N-deposition changes is the specified emission change. Under the specified emission scenario for 2050, emissions of oxidised nitrogen were reduced substantially, whereas emissions of NH3 increase to some extent, and these changes are largely reflected in the modelled concentrations and depositions. The lack of sulfur and oxidised nitrogen in the future atmosphere results in a much larger fraction of NHx being present in the form of gaseous ammonia. Predictions for wet and total deposition were broadly consistent, although the three fine-scale models resolve European emission areas and changes better than the hemisphericscale model. The biggest difference in the models is for predictions of individual N compounds. One model (EMEP) was used to explore changes in critical loads, also in conjunction with speculative climate-induced increases in NH3 emissions. These calculations suggest that the area of ecosystems that exceeds critical loads is reduced from 64% for year 2005 emissions levels to 50% for currently estimated 2050 levels. A possible climate-induced increase in NH3 emissions could worsen the situation, with areas exceeded increasing again to 57% (for a 30% NH3 emission increase).
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| 6. |
- Broman, G, et al.
(författare)
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Older women's cardiovascular responses to deep-water running
- 2006
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Ingår i: Journal of aging and physical activity. - : Human Kinetics. - 1063-8652 .- 1543-267X. ; 14:1, s. 29-40
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to examine submaximal and maximal physiological responses and perceived exertion during deep-water running with a vest compared with the responses during treadmill running in healthy elderly women. Eleven healthy women 70 ± 2 years old participated. On two different occasions they performed a graded maximal exercise test on a treadmill on land and a graded maximal exercise test in water wearing a vest. At maximal work the oxygen uptake was 29% lower (p < .05), the heart rate was 8% lower (p < .05), and the ventilation was 16% lower (p < .05) during deep-water running than during treadmill running. During submaximal absolute work the heart rate was higher during deep-water running than during treadmill running for the elderly women. The participants had lower maximal oxygen uptake, heart rate, ventilation, respiratory-exchange ratio, and rate of perceived exertion during maximal deep-water running with a vest than during maximal treadmill running. These responses were, however, higher during submaximal deep-water running than during treadmill running.
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| 7. |
- Engardt, M., et al.
(författare)
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Deposition of sulphur and nitrogen in Europe 1900-2050. Model calculations and comparison to historical observations
- 2017
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Ingår i: Tellus, Series B: Chemical and Physical Meteorology. - : Stockholm University Press. - 1600-0889 .- 0280-6509. ; 69:1, s. Article: 1328945-
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Tidskriftsartikel (refereegranskat)abstract
- As a contribution to an EU project which dealt with the effects of climate change, air pollution impacts and ecosystems, two different atmospheric chemical transport models were used to simulate the depositions of acidifying and eutrophying pollutants over Europe for the period 1900-2050. Given the unavoidable uncertainties in the historical inputs to these simulations (emissions, meteorology), we generated a new and unique data-set for the purposes of model evaluation; comprising data from the European Air Chemistry Network (EACN) in operation from 1955 to early 1980s and more recent data from the EMEP monitoring network. The two models showed similar and reasonable skills in reproducing both the EACN and EMEP observational data although the MATCH model consistently simulates higher concentrations and depositions than the EMEP model. To further assess the models' ability to reproduce the long-term trend in sulphur and nitrogen deposition we compared modelled concentrations of major ions in precipitation with data extracted from a glacier in the European Alps. While, the shape and timing of the nss-sulphate data agrees reasonably, the ice core data indicate persistently high nitrogen concentrations of oxidised and reduced nitrogen after the 1980s which does not correspond to the model simulations or data from Western Europe in the EMEP monitoring network. This study concludes that nss-sulphate deposition to Europe was already clearly elevated in the year 1900, but has now (mid-2010s) decreased to about 70% of what it was at the beginning of the last century. The deposition of oxidised nitrogen to Europe peaked during the 1980s but has since decreased to half of its maximum value; still it is 3-4 times higher than in the year 1900. The annual deposition of reduced nitrogen to Europe is currently more than two times as high as the conditions in the year 1900.
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| 10. |
- Andersson, Camilla, et al.
(författare)
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Climate change modifies air quality
- 2009
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Ingår i: Air pollution & climate change - Two sides of the same coin? Editor Håkan Pleijel, University of Gothenburg. - Stockholm : Swedish Environmental Protection Agency. - 9789162012786 ; , s. 79-87
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 11. |
- Eek, E, et al.
(författare)
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Assessment of the perceptual threshold of touch (PTT) with high-frequency transcutaneous electric nerve stimulation (Hf/TENS) in elderly patients with stroke: a reliability study
- 2003
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Ingår i: Clinical rehabilitation. - : SAGE Publications. - 0269-2155 .- 1477-0873. ; 17:8, s. 825-834
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate the inter-rater reliability and reliability between occasions of assessing the perceptual threshold of touch (PTT) with high-frequency transcutaneous electric nerve stimulation (Hf/TENS) in elderly patients with stroke. Design: A test–retest study of reliability using intraclass correlation coefficient (ICC) and limits of agreement. Setting: Geriatric rehabilitation unit. Subjects: Thirty-two consecutive patients with stroke 3 65 years of age. Main outcome measures: Two-channel current stimulator TENS CEFAR Tempo with four self-adhesive skin electrodes. The stimulator delivered a high-frequency constant current of 40 Hz. The strength of the stimulation was quantifiable and assessed in milliampere (mA). Interventions: The assessments were performed on the hands and feet by two raters. The PTT was identified as the level registered in milliampere (mA) at which the patients perceived a tingling sensation. Results: The ICC values (0.94–0.99) were shown to be good for inter-rater reliability, as well as reliability between occasions. However an additional analysis with limits of agreement showed a high level of agreement for assessment of the hand but a moderate to low agreement for assessment of the foot where some bias was also identified. Clinical acceptable reliability: 3 1 mA for the hand and 3 5 mA for the foot are so far recommended for establishing real differences in clinical measures. Conclusion: Hf/TENS shows an overall high reliability for assessing the PTT of the hand and moderate to low reliability for the foot. Additional research with exclusion of bias is needed to determine the reliability of assessing the foot.
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| 12. |
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| 13. |
- Grimby, Gunnar, 1933, et al.
(författare)
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Stroke/slaganfall
- 2008
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Ingår i: FYSS 2008 fysisk aktivitet i sjukdomsprevention och sjukdomsbehandling. - Östersund : Statens Folkhälsoinstitut. - 9789172575431 ; , s. 564-575
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 14. |
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| 15. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Observed annual surface ozone maxima and minima in northern and central Europe from 1990–2015 — latitude dependence and temporal trends
- 2019
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Ingår i: Boreal environment research. - 1239-6095. ; 24, s. 201-214
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Tidskriftsartikel (refereegranskat)abstract
- Ground-level ozone is an air pollutant that, despite reductions in precursor emission in Europe, still represents a risk to vegetation and human health. This study is based on observations of ozone concentrations ([O3]) from 25 European monitoring stations, north of the Alps within the EMEP network, during the 26-year period from 1990–2015. We analyzed the maximum and minimum hourly [O3] as well as the seasonal cycle in relation to latitude. In addition, temporal trends were studied. The maximum [O3] increased towards the south of the study area, while the yearly minimum of daytime mean increased towards the north. There was a strong correlation between the day of year when the maximum [O3] occurred and latitude: the maximum [O3] occurred earlier in the north. The maximum daytime [O3] decreased at all stations while the minimum daytime [O3] increased at most stations during the studied time period.
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| 16. |
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| 17. |
- Klingberg, Jenny, 1978, et al.
(författare)
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Ozone risk for vegetation in the future climate of Europe based on stomatal ozone uptake calculations
- 2011
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Ingår i: Tellus A. - : Stockholm University Press. ; 63, s. 174-187
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Tidskriftsartikel (refereegranskat)abstract
- The negative impacts of surface ozone (O3) on vegetation are determined by external exposure, leaf gas exchange and plant antioxidant defence capacity, all dependent on climate and CO2 concentrations. In this study the influence of climate change on simulated stomatal O3 uptake of a generic crop and a generic deciduous tree at ten European sites was investigated, using the LRTAP Mapping Manual stomatal flux model. O3 concentrations are calculated by a chemistry transport model (MATCH) for three 30-year time-windows (1961-1990, 2021-2050, 2071-2100), with constant precursor emissions and meteorology from a regional climate model (RCA3). Despite substantially increased modelled future O3 concentrations in central and southern Europe, the flux-based risk for O3 damage to vegetation is predicted to remain unchanged or decrease at most sites, mainly as a result of projected reductions in stomatal conductance under rising CO2 concentrations. Drier conditions in southern Europe are also important for this result. At northern latitudes, the current parameterisation of the stomatal conductance model suggest O3 uptake to be mainly limited by temperature. This study demonstrates the importance of accounting for the influences by climate and CO2 on stomatal O3 uptake, and of developing their representation in models, for risk assessment involving climate change.
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| 18. |
- Lindberg, Påvel G., et al.
(författare)
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Use-dependent up- and down-regulation of sensorimotor brain circuits in stroke patients
- 2007
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Ingår i: Neurorehabilitation and Neural Repair. - : SAGE Publications. - 1545-9683 .- 1552-6844. ; 21:4, s. 315-326
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To examine whether cerebral activity during passive movements decreases with time after stroke, and if reduced activity in the representation for the upper extremity can be reversed with training. Methods. Brain activity was measured by functional magnetic resonance imaging (fMRI) during passive wrist flexion-extension in 7 patients at varying time points after stroke, in a cross-sectional design. Upper limb function was also measured in all patients. Five of the patients took part in a training program and were measured again, behaviorally and with fMRI posttraining. Healthy control individuals of comparable age were also studied. Results. In patients, reduced activity over time after stroke was found for the group in the supplementary motor area (SMA), contralateral primary motor cortex, and prefrontal and parietal association areas along with ipsilateral cerebellum. Activity in most of these areas was also reduced in the patient group as compared to the control group. After a half-hour of daily training for 4 weeks with repetitive passive and active arm movements, cerebral activation increased in the pre-SMA and SMA, ipsilateral primary sensory cortex and intraparietal sulcus, and contralateral cerebellum in parallel with functional improvements of the upper limb. Areas common to both analyses included the SMA, pre-SMA, primary sensory cortex, intraparietal sulcus, and cerebellum. Conclusions. Our findings suggest that a down-regulation of sensorimotor activity occurs progressively over time as a result of inactivity and that training may reverse the reduced brain activity.
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| 19. |
- Lindberg, Påvel, et al.
(författare)
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Wallerian degeneration of the corticofugal tracts in chronic stroke : A pilot study relating diffusion tensor imaging, transcranial magnetic stimulation, and hand function
- 2007
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Ingår i: Neurorehabilitation and Neural Repair. - : SAGE Publications. - 1545-9683 .- 1552-6844. ; 21:6, s. 551-560
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Tidskriftsartikel (refereegranskat)abstract
- Objective. This study tested the hypothesis that degeneration of the corticofugal tracts (CFTs) is related to poor functional outcome in the upper limb after stroke. Methods. The authors used diffusion tensor imaging to determine the degree of white matter integrity of the CFT (FAAH/UH) in chronic stroke patients and controls. The functional integrity of the corticospinal pathway was examined using transcranial magnetic stimulation. Recruitment curves and silent period duration were measured. The relationship between FA AH/UH and functional outcome of the upper limb was also assessed using a battery of upper limb function tests. Results. In patients, FA AH/UH correlated positively with the slope of recruitment curves (RC AH/UH) and grip strength. FAAH/UH also correlated negatively with the silent period duration (SPAH/UH). According to the FA AH/UH, patients were also classified into groups with minimal or extensive Wallerian degeneration (WD). Patients with more extensive WD had poorer grip strength, dexterity, and range of movement. Conclusions. The authors' results suggest that structural and functional integrity of the CFT is essential to maintain function of the upper limb after stroke.
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| 20. |
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| 21. |
- Pettersson, AF, et al.
(författare)
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Activity level and balance in subjects with mild Alzheimer's disease
- 2002
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 13:4, s. 213-216
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Tidskriftsartikel (refereegranskat)abstract
- To clarify if Alzheimer’s disease has an impact on activity level and postural control, we examined 17 elderly diagnosed with mild Alzheimer’s disease (MMSE scores 21–29) and 18 age- and gender-matched healthy controls (MMSE scores 27–30) using the Frenchay Activities Index, Bergs Balance Scale, Timed Up & Go and Walking in a Figure of Eight. Mild AD subjects were less active and had lower scores on Bergs Balance Scale, performed Timed Up & Go in longer time and took more steps outside the Figure of Eight, as compared to healthy elderly. This study shows that motor performance is affected already at mild stages of Alzheimer’s disease and also that functional performance other than gait may also be impaired.
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