| 1. |
- Wesslén, Cevilia, et al.
(författare)
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The Arctic summer atmosphere : an evaluation of reanalyses using ASCOS data
- 2014
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 14:5, s. 2605-2624
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Tidskriftsartikel (refereegranskat)abstract
- The Arctic has experienced large climate changes over recent decades, the largest for any region on Earth. To understand the underlying reasons for this climate sensitivity, reanalysis is an invaluable tool. The Arctic System Reanalysis (ASR) is a regional reanalysis, forced by ERA-Interim at the lateral boundaries and incorporating model physics adapted to Arctic conditions, developed to serve as a state-of-the-art, high-resolution synthesis tool for assessing Arctic climate variability and monitoring Arctic climate change. We use data from Arctic Summer Cloud-Ocean Study (ASCOS) to evaluate the performance of ASR and ERAInterim for the Arctic Ocean. The ASCOS field experiment was deployed on the Swedish icebreaker Oden north of 87 degrees N in the Atlantic sector of the Arctic during August and early September 2008. Data were collected during the transits from and to Longyearbyen and the 3-week ice drift with Oden moored to a drifting multiyear ice floe. These data are independent and detailed enough to evaluate process descriptions. The reanalyses captures basic meteorological variations coupled to the synoptic-scale systems, but have difficulties in estimating clouds and atmospheric moisture. While ERAInterim has a systematic warm bias in the lowest troposphere, ASR has a cold bias of about the same magnitude on average. The results also indicate that more sophisticated descriptions of cloud microphysics in ASR did not significantly improve the modeling of cloud properties compared to ERA-Interim. This has consequences for the radiation balance, and hence the surface temperature, and illustrate how a modeling problem in one aspect of the atmosphere, here the clouds, feeds back to other parameters, especially near the surface and in the boundary layer.
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| 2. |
- Acosta Navarro, Juan Camilo, et al.
(författare)
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Global emissions of terpenoid VOCs from terrestrial vegetation in the last millennium
- 2014
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Ingår i: Journal of Geophysical Research - Atmospheres. - : Wiley-Blackwell. - 2169-897X .- 2169-8996. ; 119:11, s. 6867-6885
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the millennial variability (1000 A.D.-2000 A.D.) of global biogenic volatile organic compound (BVOC) emissions by using two independent numerical models: The Model of Emissions of Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene, and sesquiterpene, and Lund-Potsdam-Jena-General Ecosystem Simulator (LPJ-GUESS), for isoprene and monoterpenes. We found the millennial trends of global isoprene emissions to be mostly affected by land cover and atmospheric carbon dioxide changes, whereas monoterpene and sesquiterpene emission trends were dominated by temperature change. Isoprene emissions declined substantially in regions with large and rapid land cover change. In addition, isoprene emission sensitivity to drought proved to have significant short-term global effects. By the end of the past millennium MEGAN isoprene emissions were 634 TgC yr-1 (13% and 19% less than during 1750-1850 and 1000-1200, respectively), and LPJ-GUESS emissions were 323 TgC yr-1(15% and 20% less than during 1750-1850 and 1000-1200, respectively). Monoterpene emissions were 89 TgC yr-1(10% and 6% higher than during 1750-1850 and 1000-1200, respectively) in MEGAN, and 24 TgC yr-1 (2% higher and 5% less than during 1750-1850 and 1000-1200, respectively) in LPJ-GUESS. MEGAN sesquiterpene emissions were 36 TgC yr-1(10% and 4% higher than during 1750-1850 and 1000-1200, respectively). Although both models capture similar emission trends, the magnitude of the emissions are different. This highlights the importance of building better constraints on VOC emissions from terrestrial vegetation.
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| 3. |
- Ekman, M., et al.
(författare)
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PMH30 The Societal Cost of Depression: Evidence from 10,000 Swedish Patients in Psychiatric Care
- 2012
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Ingår i: Value in Health. - 1098-3015. ; 15:4, s. A87-A87
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Konferensbidrag (refereegranskat)abstract
- Objectives Depression is a major health problem. Previous studies on the cost of depression have mainly taken a primary care perspective. Such studies do not include all patients with depression, and should be completed by cost estimates from psychiatric care. The objectives of this study were to estimate the annual societal cost of depression per patient in psychiatric care in Sweden, and to relate costs to disease severity, depressive episodes, hospitalization, and patient functioning. Methods Retrospective resource use data in inpatient and outpatient care for 2006-2008, as well as ICD-10 diagnoses and Global Assessment of Functioning (GAF), were obtained from Northern Stockholm psychiatric clinic with a catchment area including 47% of the adult inhabitants in Stockholm city. This data set was combined with national register data on prescription pharmaceuticals and sick leave to estimate the societal cost of depression. Results The study included 10,593 patients (63% women). The average annual societal cost per patient was around USD 21,000 in 2006-2008. The largest cost item was indirect costs due to productivity losses (89%), and the second largest was outpatient care (6%). Patients with mild, moderate or severe depression had an average cost of approximately USD 18,000, USD 21,000, and USD 29,000, respectively. Total costs were significantly higher during depressive episodes, for patients with co-morbid psychosis or anxiety, for hospitalized patients, and for patients with low GAF scores. Conclusions The largest share of societal costs for patients with depression in psychiatric care is indirect. The total costs were higher than previously reported from a primary care setting, and strongly related to hospitalization, episodes of active depression, and global functioning. This suggests that effective treatment and rehabilitation that avoid depressive episodes and hospitalization may not only improve patient health, but also reduce the societal cost of depression.
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| 4. |
- Ekman, M., et al.
(författare)
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The societal cost of bipolar disorder in Sweden
- 2013
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Ingår i: Social Psychiatry and Psychiatric Epidemiology. - : Springer Science and Business Media LLC. - 0933-7954 .- 1433-9285. ; 48:10, s. 1601-1610
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Tidskriftsartikel (refereegranskat)abstract
- There is a lack of comprehensive cost-of-illness studies in bipolar disorder, in particular studies based on patient-level data. The purpose of this study was to estimate the societal cost of bipolar disorder and to relate costs to disease severity, depressive episodes, hospitalisation and patient functioning. Retrospective resource use data in inpatient and outpatient care during 2006-2008, as well as ICD-10 diagnoses and Global Assessment of Functioning (GAF) scores, were obtained from the Northern Stockholm psychiatric clinic with a catchment area including 47 % of the adult inhabitants in Stockholm. This dataset was combined with national register data on prescription pharmaceuticals and sick leave to estimate the societal cost of bipolar disorder. The study was conducted from a societal perspective, with indirect costs valued according to the human capital method. The average annual cost per patient was a,not sign28,011 in 2008 (n = 1,846). Indirect costs due to sick leave and early retirement represented 75 %, inpatient costs 13 %, outpatient costs 8 %, pharmaceuticals 2 % and community care another 2 % of the total cost. Total costs were considerably higher during mood episodes (six times higher than in remission), for hospitalised patients (a,not sign55,500 vs. a,not sign22,200) and for patients with low GAF scores. The high cost of bipolar disorder is driven primarily by indirect costs. Costs were strongly associated with mood episodes, hospitalisations and low GAF scores. This suggests that treatment that reduces the risk for relapses and hospitalizations and improve functioning may decrease both the societal cost of bipolar disorder and patient suffering.
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| 5. |
- Ekman, M., et al.
(författare)
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The societal cost of depression: Evidence from 10,000 Swedish patients in psychiatric care
- 2013
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Ingår i: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327 .- 1573-2517. ; 150:3, s. 790-797
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Depression cost studies have mainly taken a primary care perspective and should be completed with cost estimates from psychiatric care. The objectives of this study were to estimate the societal per-patient cost of depression in specialized psychiatric care in Sweden, and to relate costs to disease severity, depressive episodes, hospitalization, and patient functioning. Methods: Retrospective resource use data in inpatient and outpatient care for 2006-2008, as well as lCD-10 diagnoses and Global Assessment of Functioning (GAF), were obtained from the Northern Stockholm psychiatric clinic (covering half of Stockholm's population aged 18 years and above). As a complement, data from national registers on pharmaceuticals and sick leave were used in order to estimate the societal cost of depression. Results: Based on 10,430 patients (635, women), the mean annual per patient cost was (sic)17, 279 in 2008. The largest cost item was indirect costs due to productivity losses (88%), followed by outpatient care (6%). Patients with mild and severe depression had average costs of (sic)14,200 and (sic)21,500, respectively. Total costs were substantially higher during depressive episodes, among patients with co-morbid psychosis or anxiety, for hospitalized patients, and for patients with poor functioning. Limitations: Primary care costs and costs for reduced productivity at work were not included. Conclusions: The main cost item among depression patients in psychiatric care was indirect costs. Costs were higher than previously reported for primary care, and strongly related to hospitalization, depressive episodes, and low functioning. This suggests that effective treatment that avoids depressive episodes and hospitalization may reduce society's costs for depression.
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| 6. |
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| 7. |
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| 8. |
- Ekman, M., et al.
(författare)
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The Societal Cost of Schizophrenia in Sweden
- 2013
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Ingår i: Journal of Mental Health Policy and Economics. - 1091-4358. ; 16:1, s. 13-25
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Tidskriftsartikel (refereegranskat)abstract
- Background: Schizophrenia is a disabling psychiatric disorder that has severe consequences for patients and their families. Moreover, the expensive treatment of schizophrenia imposes a burden on health care providers and the wider society. Existing cost estimates for Sweden, however, are based on relatively small patient populations and need to be confirmed in a large register-based study. Aims of the Study: To investigate the health care resource utilization and cost-of-illness in patients with schizophrenia in Sweden and to relate the costs to hospitalizations and global assessment of functioning (GAF). Methods: Hospital-based registry data were combined with national registry data from a large patient population to get reliable estimates of the costs of schizophrenia in Sweden. Schizophrenia was defined by ICD-10 codes F20; F21; F23.1,2,8,9; F25.1,8,9. Registry data on socio-demographics and disease-related healthcare resource use in outpatient and inpatient care were obtained from Northern Stockholm Psychiatry. Data on pharmaceuticals were obtained from the National Board of Health and Welfare, and data on sick leave and early retirement were obtained from the Swedish Social Insurance Agency. Costs for community mental health care were not available at the individual level, but were estimated based on previous studies and aggregate cost data from Stockholm. Resource use data from the registries were combined with unit costs from publicly available sources. The study was conducted from a societal perspective, with indirect costs valued according to the human capital method. Results: The average annual psychiatric cost per patient with schizophrenia in 2008 was 42 700 (95% CI: 41 500 44 000), based on a sample of 2 161 patients. To this should be added costs for community mental health care of 12 400 per patient, giving a total cost of 55 100 per patient. The two largest cost items in the total costs were indirect costs due to lost productivity (60%) and community mental health care (22% of the total cost). Patients who were hospitalized in 2008 had greater psychiatric costs than those who were not, (sic)71 700 vs. (sic)37 700 (p<0.0001). Psychiatric costs were significantly and negatively correlated with GAF (p<0.001). Discussion: The major strengths of the study are the relatively large sample, and the linkage of patient-level clinical data on inpatient and outpatient care with national registry data on prescription pharmaceuticals, and days on social insurance. A limitation was that costs for informal care and primary care were not included in the data, but previous studies suggest that these costs items are small compared to other costs for schizophrenia. Implications for Health Policies and Future Research: Costs were strongly related to hospitalization and GAF, suggesting that attempts to improve global functioning and avoid hospitalizations by means of effective treatment and rehabilitation might not only decrease suffering for patients and relatives, but also reduce the societal cost of schizophrenia. A detailed knowledge of the societal costs can also be helpful in evaluating the cost-effectiveness of new treatment strategies to improve the care for patients with schizophrenia.
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| 9. |
- Ekman, M., et al.
(författare)
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Tool qualification for safety related systems
- 2014
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Ingår i: Ada User Journal. - 1381-6551. ; 35, s. 47-54
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Tidskriftsartikel (refereegranskat)abstract
- Tools used in the development of safety related software applications need to be qualified as safe. That is, the tools cannot be allowed to introduce hazardous faults into the application, e.g., a compiler shall not generate dangerous code due to failure of the compiler. In many cases laws and regulations require the product development of safety related applications to comply with industry sector specific safety standards. Examples of such standards include EN50129/50128 for railway applications, ISO/EN13849 for machines with moving parts, DO-178B/C for avionics, or IS026262 for cars. These standards require the use of a rigorous development and maintenance process. The standards are also mainly intended to be used when developing systems from scratch. However, most development and test tools are not developed from scratch according to the rigorous processes of these standards. In order to address this issue, some of the standards provide means for qualifying existing tools as a more lightweight and pragmatic alternative to a regular certification process. In this paper we analyze the concept of these qualification approaches. The result of the analysis in our contribution includes a set of approaches that can be applied individually or as a combination in order to reduce the effort needed for qualifying tools. As a running example we use one of the most flexible but at the same time dangerous, even prohibited, maintenance techniques available: dynamic instrumentation of executing code. With this example, we describe how exceptions in these standards can be utilized in order to qualify a dynamic instrumentation tool with a minimal effort, without following the process of tool certification as defined by the standards.
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| 10. |
- Kirkevag, A., et al.
(författare)
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Aerosol-climate interactions in the Norwegian Earth System Model-NorESM1-M
- 2013
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 6:1, s. 207-244
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study is to document and evaluate recent changes and updates to the module for aerosols and aerosol-cloud-radiation interactions in the atmospheric module CAM4-Oslo of the core version of the Norwegian Earth System Model (NorESM), NorESM1-M. Particular attention is paid to the role of natural organics, sea salt, and mineral dust in determining the gross aerosol properties as well as the anthropogenic contribution to these properties and the associated direct and indirect radiative forcing. The aerosol module is extended from earlier versions that have been published, and includes life-cycling of sea salt, mineral dust, particulate sulphate, black carbon, and primary and secondary organics. The impacts of most of the numerous changes since previous versions are thoroughly explored by sensitivity experiments. The most important changes are: modified prognostic sea salt emissions; updated treatment of precipitation scavenging and gravitational settling; inclusion of biogenic primary organics and methane sulphonic acid (MSA) from oceans; almost doubled production of land-based biogenic secondary organic aerosols (SOA); and increased ratio of organic matter to organic carbon (OM/OC) for biomass burning aerosols from 1.4 to 2.6. Compared with in situ measurements and remotely sensed data, the new treatments of sea salt and dust aerosols give smaller biases in near-surface mass concentrations and aerosol optical depth than in the earlier model version. The model biases for mass concentrations are approximately unchanged for sulphate and BC. The enhanced levels of modeled OM yield improved overall statistics, even though OM is still underestimated in Europe and overestimated in North America. The global anthropogenic aerosol direct radiative forcing (DRF) at the top of the atmosphere has changed from a small positive value to -0.08 W m(-2) in CAM4-Oslo. The sensitivity tests suggest that this change can be attributed to the new treatment of biomass burning aerosols and gravitational settling. Although it has not been a goal in this study, the new DRF estimate is closer both to the median model estimate from the AeroCom intercomparison and the best estimate in IPCC AR4. Estimated DRF at the ground surface has increased by ca. 60 %, to -1.89 W m(-2). We show that this can be explained by new emission data and omitted mixing of constituents between updrafts and downdrafts in convective clouds. The increased abundance of natural OM and the introduction of a cloud droplet spectral dispersion formulation are the most important contributions to a considerably decreased estimate of the indirect radiative forcing (IndRF). The IndRF is also found to be sensitive to assumptions about the coating of insoluble aerosols by sulphate and OM. The IndRF of -1.2 W m(-2), which is closer to the IPCC AR4 estimates than the previous estimate of -1.9 W m(-2), has thus been obtained without imposing unrealistic artificial lower bounds on cloud droplet number concentrations.
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