| 1. |
- Giesler, Reiner, et al.
(author)
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Catchment-scale dissolved carbon concentrations and exportestimates across six subarctic streams in northern Sweden
- 2014
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In: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 11:2, s. 525-537
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Journal article (peer-reviewed)abstract
- Climatic change is currently enhancing permafrost thawing and the flow of water through the landscape in subarctic and arctic catchments, with major consequences for the carbon export to aquatic ecosystems. We studied stream water carbon export in several tundra-dominated catchments in northern Sweden. There were clear seasonal differences in both dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) concentrations. The highest DOC concentrations occurred during the spring freshet while the highest DIC concentrations were always observed during winter baseflow conditions for the six catchments considered in this study. Long-term trends for the period 1982 to 2010 for one of the streams showed that DIC concentrations has increased by 9% during the 28 yr of measurement while no clear trend was found for DOC. Similar increasing trends were also found for conductivity, Ca and Mg. When trends were discretized into individual months, we found a significant linear increase in DIC concentrations with time for September, November and December. In these subarctic catchments, the annual mass of C exported as DIC was in the same order of magnitude as DOC; the average proportion of DIC to the total dissolved C exported was 61% for the six streams. Furthermore, there was a direct relationship between total runoff and annual dissolved carbon fluxes for these six catchments. These relationships were more prevalent for annual DIC exports than annual DOC exports in this region. Our results also highlight that both DOC and DIC can be important in high-latitude ecosystems. This is particularly relevant in environments where thawing permafrost and changes to subsurface ice due to global warming can influence stream water fluxes of C. The large proportion of stream water DIC flux also has implications on regional C budgets and needs to be considered in order to understand climate-induced feedback mechanisms across the landscape.
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| 2. |
- Haghsheno, Mohammad-Ali, et al.
(author)
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Low 25-OH Vitamin D Level is Associated with Benign Prostatic Enlargement (BPE).
- 2013
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In: The Journal of urology. - : Ovid Technologies (Wolters Kluwer Health). - 1527-3792 .- 0022-5347. ; 190:2, s. 608-614
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Journal article (peer-reviewed)abstract
- PURPOSE: To test the hypothesis that low levels of vitamin D were associated with Benign Prostatic Enlargement (BPE). We also studied whether body composition, sex hormones, serum SHBG, albumin corrected serum calcium, adiponectin and lipid statuses were associated with BPE. MATERIALS AND METHODS: 184 representative randomly selected men aged 72 - 76 years, enrolled in the Gothenburg arm of the MrOs study, were investigated. Men with a medical history of prostate cancer, prostate operation or medication for BPE were excluded leaving 155 men to be analyzed. A cross-sectional study was conducted in which BPE, as measured by the total prostate gland volume, was related to clinical, anthropometric, endocrine and metabolic factors, using univariate and multivariate analyses with regression models. RESULTS: The median prostate volume was 40 ml. In multivariate models only 25-OH vitamin D, albumin corrected serum calcium, serum SHBG and HDL-cholesterol were significantly and inversely associated with large prostate glands. CONCLUSION: The present report adds four independent factors associated with BPE: Low levels of 25-OH vitamin D, serum calcium, SHBG and HDL-cholesterol.
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| 4. |
- Stenevi Lundgren, S., et al.
(author)
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Low physical activity is related to clustering of risk factors for fracture—a 2-year prospective study in children
- 2017
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In: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 28:12, s. 3373-3378
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Journal article (peer-reviewed)abstract
- Summary: The study investigates the effect of physical activity (PA) on a composite score for fracture risk in pre-pubertal children. Low PA in children is related to the composite score for fracture risk and the pre-pubertal years seem to be a period when PA positively affects the score. Introduction: This study evaluates if PA in children is related to clustering of risk factors for fracture. Research questions are the following: (i) What is the effect of physical activity (PA) on single traits and a composite score for fracture risk? (ii) Could this score be used to identify the level of PA needed to reach beneficial effects? Methods: This prospective population-based study included 269 children, aged 7–9 years at baseline while 246 attended the 2-year follow-up. We estimated duration of PA by questionnaires and measured traits that independently predict fractures. We then calculated gender specific Z-scores for each variable. The mean Z-score of all traits was used as a composite score for fracture risk. We tested correlation between duration of PA, each trait, and the composite score and group differences between children in different quartiles of PA. Results: At baseline, we found no correlation between duration of PA and any of the traits or the composite score. At follow-up, we found a correlation between PA and the composite score. Physical activity had an effect on composite score, and children in the lowest quartiles of PA had unbeneficial composite score compared to children in the other quartiles. Conclusion: Low PA in children is related to clustering of risk factors for fracture, and the pre-pubertal years seem to be a period when PA positively affects the composite score.
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| 5. |
- Andersson, S., et al.
(author)
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Sulfur recirculation for increased electricity production in Waste-to-Energy plants
- 2014
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In: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 34:1, s. 67-78
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Journal article (peer-reviewed)abstract
- Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Goteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop. The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO3 concentrations, which may otherwise induce low temperature corrosion. In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 degrees C and 525 degrees C) compared to the reference exposure. The corrosion rates were reduced by 60-90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 degrees C with sulfur recirculation in operation were similar or lower compared to those measured at 450 degrees C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion.
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| 6. |
- Andrén, Ove, 1963-, et al.
(author)
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MUC-1 gene is associated with prostate cancer death : a 20-year follow-up of a population-based study in Sweden
- 2007
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In: British Journal of Cancer. - London : Harcourt Publishers. - 0007-0920 .- 1532-1827. ; 97:6, s. 730-734
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Journal article (peer-reviewed)abstract
- Anti-adhesion mucins have proven to play an important part in the biology of several types of cancer. Therefore, we test the hypothesis that altered expression of MUC-1 is associated with prostate cancer progression. We retrieved archival tumour tissue from a population-based cohort of 195 men with localised prostate cancer (T1a-b, Nx, M0) that has been followed for up to 20 years with watchful waiting. Semi-automated, quantitative immunohistochemistry was undertaken to evaluate MUC-1 expression. We modelled prostate cancer-specific death as a function of MUC-1 levels accounting for age, Gleason grade and tumour extent, and calculated age-adjusted and multivariate adjusted hazard ratios (HR). Men that had tumours with an MUC-intensity lower or higher than normal tissue had a higher risk of dying in prostate cancer, independent of tumour extent and Gleason score (HR 5.1 and 4.5, respectively). Adjustment for Gleason grade and tumour stage did not alter the results. Men with a Gleason score >=7 and MUC-1 deviating from the normal had a 17 (RR=17.1 95% confidence interval=2.3–128) times higher risk to die in prostate cancer compared with men with Gleason score <7 and normal MUC-1 intensity. In summary, our data show that MUC-1 is an independent prognostic marker for prostate cancer death.
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| 9. |
- Karlsson, Stefan M., et al.
(author)
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Illuminance Flow Estimation by Regression
- 2010
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In: International Journal of Computer Vision. - Amsterdam : Elsevier. - 0920-5691 .- 1573-1405. ; 90:3, s. 304-312
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Journal article (peer-reviewed)abstract
- We investigate the estimation of illuminance flow using Histograms of Oriented Gradient features (HOGs). In a regression setting, we found for both ridge regression and support vector machines, that the optimal solution shows close resemblance to the gradient based structure tensor (also known as the second moment matrix). Theoretical results are presented showing in detail how the structure tensor and the HOGs are connected. This relation will benefit computer vision tasks such as affine invariant texture/object matching using HOGs. Several properties of HOGs are presented, among others, how many bins are required for a directionality measure, and how to estimate HOGs through spatial averaging that requires no binning.
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| 10. |
- Klintberg, Lena, et al.
(author)
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A large stroke, high force paraffin phase transition actuator
- 2002
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In: Sensors and Actuators A-Physical. - 0924-4247 .- 1873-3069. ; 96:2-3, s. 189-195
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Journal article (peer-reviewed)abstract
- An actuator that uses the volume expansion related to the solid-to-liquid phase transition of paraffin wax has been fabricated and evaluated. The actuator consists of a ring-shaped paraffin cavity confined by two joint silicon diaphragms with rigid centers. When the paraffin is melted, the resulting hydrostatic pressure deflects the joined rigid centers in one direction only. The magnitude of the deflection is primarily a function of the geometrical relation between the two diaphragms, giving the opportunity to tailor the behavior of the actuator in a large range. Conventional IC-processing techniques have been used to fabricate a prototype with a width of 68 mm and a thickness of 825 μm. The prototype attained a maximum deflection of ca. 90 μm. Loaded with 3 N it still exhibits a deflection of ca. 75 μm. The device can be used as a thermal switch.
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