| 1. |
- Al-Rubaei, Ahmed, et al.
(författare)
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Long-term hydraulic and treatment performance of a 19-year old constructed stormwater wetland : Finally maturated or in need of maintenance?
- 2016
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Ingår i: Ecological Engineering. - : Elsevier BV. - 0925-8574 .- 1872-6992. ; 95, s. 73-82
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Tidskriftsartikel (refereegranskat)abstract
- Constructed stormwater wetlands (CSWs) are a commonly used measure for stormwater retention and quality treatment. However, although questions have been raised about the long-term performance of CSWs, only a few studies have targeted this issue and none have evaluated the performance of CSWs more than approximately 5–10 years old. Further, most studies have not examined the development of the long-term performance of CSWs but delivered a snapshot at a certain point of time. The present study investigated the performance of a 19-year-old CSW in Växjö, Sweden, treating stormwater from a 320-ha urban catchment. Besides removal of sediment from the CSW’s forebay, no other maintenance had been conducted. However, regular inspections had been performed. The results of the present sampling campaign were compared to two existing datasets collected at the same CSW after three years of operation in 1997 and nine years of operation in 2003. The CSW was found to provide efficient peak flow reduction and, depending on the event characteristics, also volume reduction. It still treated stormwater effectively: removal of Cd, Cu, Pb, Zn, TSS and TP event mean concentrations were between 89 and 96%, whereas mean concentrations of TN were reduced by 59%. The load removal efficiencies were even higher. Comparative analysis of the three monitoring periods based on the load removal efficiency revealed that the CSW, despite the lack of maintenance, performed more efficiently and stably for most pollutants compared to when newly constructed. This underlines the importance of the establishment and maturation of constructed wetland systems. Overall, the results showed that CSWs are resilient systems, which if designed well and regularly inspected to prevent major issues, can work efficiently for at least two decades.
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| 2. |
- Al-Rubaei, Ahmed, et al.
(författare)
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Long-term hydraulic performance of stormwater infiltration systems : a field survey
- 2013
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Ingår i: NOVATECH 2013.
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Konferensbidrag (refereegranskat)abstract
- This paper examined the factors influencing the long-term hydraulic performance of some stormwater infiltration systems (swale and two types of permeable pavements) in Växjö, southern Sweden. The infiltration capacities of 9 permeable pavements and 2 swales sites, all with different ages ranging from 1 year to 14 years, were measured using replicate double ring infiltrometers. The sites were either constructed of swale (2), interlocking concrete pavers (ICP) filled with gravel (2), concrete grid pavers (CGP) filled with gravel (3), or concrete grid pavers (CGP) filled with grass (4). The results of this study showed that the long-term behaviour of the infiltration capacity relies largely on the type and age of the system and the type of joint filling (gravel and grass). Furthermore, the study showed that the 11 year old concrete grid pavers filled with grass had the highest infiltration capacity (4.80 + 2.46 mm/min), whilst the 9 and 14 year old swales had the lowest infiltration capacity (0.10 + 0.00 mm/min).
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| 3. |
- Al-Rubaei, Ahmed Mohammed, et al.
(författare)
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Effectiveness of a 19-Year Old Combined Pond-Wetland System in Removing Particulate and Dissolved Pollutants
- 2017
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Ingår i: Wetlands (Wilmington, N.C.). - : Springer. - 0277-5212 .- 1943-6246. ; 37:3, s. 485-496
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Tidskriftsartikel (refereegranskat)abstract
- This study monitored the stormwater runoff quantity and quality treatment performance of a 6.8 ha 19-year old combined pond-wetland system, located in south Sweden, over one year. The mean volume reductions for 53 storm events for the pond and wetland were 40% and 28%, respectively, while the mean flow reductions were 60% and 76%, respectively. Pollutant concentrations in the influent to the wetland were highly variable. The pond-wetland system could efficiently remove an average of 91%, 80%, 94%, 91%, 83% and 92% of TSS, TP, particulate Cd, Cu, Pb, and Zn, respectively, whereas the removal of particulate and dissolved Ni was highly variable with an average of 67% ± 62% and −5% ± 41%, respectively. The removal of TN, NH4-N and NO3 + NO2-N was highly variable with an average of 45% ± 27%, 12% ± 96% and 45% ± 43%, respectively. These removal percentages are high in comparison to other studies and underline that relatively old systems can also provide efficient treatment. Although the pond accounted for a substantial reduction of pollutant concentration, the wetland significantly enhanced both the treatment performance and the peak flow reduction. This underlines that a combined pond/wetland system is a more beneficial solution than a pond only. The pollutant removal efficiency was significantly influenced by some factors including Antecedent Dry Days, seasonal variations, air temperature, retention times, rainfall depth and duration, and peak rainfall intensity.
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| 4. |
- Al-Rubaei, Ahmed Mohammed, et al.
(författare)
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Long-Term Treatment Efficiency of a Constructed Stormwater Wetland: Preliminary Results
- 2014
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Konferensbidrag (refereegranskat)abstract
- Constructed stormwater wetlands (CSWs) are commonly used in Sweden and worldwide because of their high efficiency in urban stormwater management. However, questions have been raised about the long-term performance of CSWs. This study investigated the performance of a 19-year-old constructed wetland, which was designed to treat the stormwater from a 320-ha catchment located in the city of Växjö, southern Sweden. The system has not been maintained since its construction in 1994. The results of the present study were compared with results obtained from a previous study conducted by Växjö Municipality in 1997. The results showed that the CSW significantly reduced peak flows by 72%. High concentration reductions were found for Cd, Cr, Cu, Zn, Pb, TSS and TP (90, 89, 91, 90, 96, 96 and 86%, respectively). TN concentrations were reduced by 61%. The results indicated that lack of maintenance had no effect on the performance of wetland system during this long period of operation (19 years). In contrast, especially the removal of Cu and nitrogen was enhanced compared to 1997, which may be due to maturing of the system. The results show that CSWs are resilient systems, which (provided that design is sufficient) can work efficiently for at least two decades.
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| 5. |
- Andersen, Malin, 1977-, et al.
(författare)
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In silico detection of sequence variations modifying transcriptional regulation
- 2008
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Ingår i: PloS Computational Biology. - : Public Library of Science (PLoS). - 1553-734X .- 1553-7358. ; 4:1, s. e5-
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Tidskriftsartikel (refereegranskat)abstract
- Identification of functional genetic variation associated with increased susceptibility to complex diseases can elucidate genes and underlying biochemical mechanisms linked to disease onset and progression. For genes linked to genetic diseases, most identified causal mutations alter an encoded protein sequence. Technological advances for measuring RNA abundance suggest that a significant number of undiscovered causal mutations may alter the regulation of gene transcription. However, it remains a challenge to separate causal genetic variations from linked neutral variations. Here we present an in silico driven approach to identify possible genetic variation in regulatory sequences. The approach combines phylogenetic footprinting and transcription factor binding site prediction to identify variation in candidate cis-regulatory elements. The bioinformatics approach has been tested on a set of SNPs that are reported to have a regulatory function, as well as background SNPs. In the absence of additional information about an analyzed gene, the poor specificity of binding site prediction is prohibitive to its application. However, when additional data is available that can give guidance on which transcription factor is involved in the regulation of the gene, the in silico binding site prediction improves the selection of candidate regulatory polymorphisms for further analyses. The bioinformatics software generated for the analysis has been implemented as a Web-based application system entitled RAVEN ( regulatory analysis of variation in enhancers). The RAVEN system is available at http://www.cisreg.ca for all researchers interested in the detection and characterization of regulatory sequence variation.
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| 6. |
- Araghi, Marzieh, et al.
(författare)
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Use of moist oral snuff (snus) and pancreatic cancer : Pooled analysis of nine prospective observational studies
- 2017
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 141:4, s. 687-693
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Tidskriftsartikel (refereegranskat)abstract
- While smoking is a well-established risk factor for pancreatic cancer, the effect of smokeless tobacco is less well understood. We used pooled individual data from the Swedish Collaboration on Health Effects of Snus Use to assess the association between Swedish snus use and the risk of pancreatic cancer. A total of 424,152 male participants from nine cohort studies were followed up for risk of pancreatic cancer through linkage to health registers. We used shared frailty models with random effects at the study level, to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for confounding factors. During 9,276,054 person-years of observation, 1,447 men developed pancreatic cancer. Compared to never-snus use, current snus use was not associated with risk of pancreatic cancer (HR 0.96, 95% CI 0.83-1.11) after adjustment for smoking. Swedish snus use does not appear to be implicated in the development of pancreatic cancer in men. Tobacco smoke constituents other than nicotine or its metabolites may account for the relationship between smoking and pancreatic cancer. What's new? While smoking is a well-established risk factor for pancreatic cancer, the effect of smokeless tobacco is less well understood. Smokeless tobacco like snus yields lower exposure to tobacco carcinogens compared with smoking, because it does not undergo combustion, but delivers an equivalent dose of nicotine. Using pooled individual data from the Swedish Collaboration on Health Effects of Snus Use, here the authors show that Swedish snus use does not appear to be implicated in the development of pancreatic cancer in men. Tobacco smoke constituents other than nicotine or its metabolites may account for the relationship between smoking and pancreatic cancer.
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| 7. |
- Ayob, Mohd Nasir, et al.
(författare)
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Small-Scale Renewable Energy Converters for Battery Charging
- 2018
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Ingår i: Journal of Marine Science and Engineering. - : MDPI. - 2077-1312. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents two wave energy concepts for small-scale electricity generation. In the presented case, these concepts are installed on the buoy of a heaving, point-absorbing wave energy converter (WEC) for large scale electricity production. In the studied WEC, developed by Uppsala University, small-scale electricity generation in the buoy is needed to power a tidal compensating system designed to increase the performance of the WEC in areas with high tides. The two considered and modeled concepts are an oscillating water column (OWC) and a heaving point absorber. The results indicate that the OWC is too small for the task and does not produce enough energy. On the other hand, the results show that a hybrid system composed of a small heaving point absorber combined with a solar energy system would be able to provide a requested minimum power of around 37.7W on average year around. The WEC and solar panel complement each other, as the WEC produces enough energy by itself during wintertime (but not in the summer), while the solar panel produces enough energy in the summer (but not in the winter).
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| 8. |
- Bartholdson, Örjan, et al.
(författare)
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Does paying pay off? : paying for ecosystem services and exploring alternative possibilities
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The ongoing degradation of ecosystems threaten future food production and the international community thus urgently has to plan for how to secure fundamental life-support services for the future, so called ecosystem services (ES). Examples of such ES are climate regulation, nutrient cycles, fresh water provision, etc.This report is focused on two distinct strategies to make land users in tropical rainforest areas continue to provide ecosystem services. The first approach, Payment for Ecosystem Services (PES), is an economic instrument designed at global and national levels. Several PES schemes are currently implemented in a global context where increasing human demands for food, fibre and fuel are accelerating competition for land. The overall aim of the PES projects covered by this report is to lower the emission of green house gas on national and global levels and they are especially directed towards forest areas. The PES projects specify that specific rural groups are paid if they agree to protect, manage or restore the ecosystem service provisioning system within their forest territories. This report highlights that many PES initiatives are being implemented with a ‘conservation perspective’, rather than seeing ecosystem services as integrated with production and livelihoods. There are also alternative strategies to manage ecosystem services. In this report we put an emphasis on an approach where production and conservation are planned for within the same landscape and production systems. Many smallholders already integrate and maintain ecosystem services in their agricultural/forest production systems in a long-term perspective, while producing food, fibre and fuel for the households’ own consumption as well as for sale. In such a system, the local communities are totally dependent on the ecosystem services to re-generate conditions for their agricultural production and/or forest extraction. The focus in such farming-forestry systems, using little or no inputs, which are totally dependent on renewable resources, is on how to increase agricultural/forest production by supporting local ecosystem services, such as soil fertility and structure, pollination, micro climate, biological control of crop pests, etc. The ecosystem services functions, such as carbon sequestration, then emerge as a ‘by-product’ out of these production systems. Increased soil humus in the soil and biomass accumulation are other examples of such ‘by-products’. We want to illustrate potentials and challenges with the aforementioned two approaches to secure ecosystem provisions, and how they are articulated within their specific contexts. This report explores these two approaches by examining case-studies in tropical forest areas in Peru, Brazil, Tanzania and Vietnam, as well as the experiences of EU-designed PES schemes for subsidies/support so as to achieve environmental protection in Sweden.
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| 9. |
- Bay, Annika, et al.
(författare)
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Patient reported outcomes are associated with physical activity level in adults with congenital heart disease.
- 2017
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 243, s. 174-179
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In general, adults with congenital heart disease (CHD) have impaired exercise capacity, and approximately 50% do not reach current recommendations on physical activity. Herein we analysed factors associated with physical activity level (PAL) in adults with CHD by using patient-reported outcomes (PRO).METHODS: Patients with CHD (n=471) were randomly selected from the national register on CHD and categorized according to complexity of lesions - simple (n=172, 39.1±14.6years), moderate (n=212, 39±14.1years), and severe (n=87, 31.7±10.7years). Participants completed a standardized questionnaire measuring PRO-domains including PAL. Variables associated with PAL were tested in multivariate logistic regression.RESULTS: PAL was categorized into high (≥3 METs ≥2.5h/week, n=192) and low (≥3 METs <2.5h/week, n=279). Patients with low PAL were older (42.6 vs. 35.8years, p≤0.001), had more prescribed medications (51% vs. 39%, p=0.009), more symptoms (25% vs. 16%, p=0.02) and comorbidity (45% vs. 34% p=0.02). Patients with low PAL rated a lower quality of life (76.6 vs. 83.4, p<0.001), satisfaction with life (25.6 vs. 27.3, p=0.003), a lower Physical Component Summary score (PCS) (78.1 vs. 90.5, p<0.001) and Mental Component Summary score (MCS) (73.5 vs. 79.5, p<0.001). Complexity of heart lesion was not associated with PAL. The included PROs - separately tested in the model, together with age were associated with PAL.CONCLUSIONS: PCS and MCS are stronger associated with PAL than age and medical factors. The use of these PROs could therefore provide valuable information of benefit for individualized advice regarding physical activity to patients with CHD.
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| 10. |
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