| 1. |
- Yaghootkar, Hanieh, et al.
(författare)
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Genetic Studies of Leptin Concentrations Implicate Leptin in the Regulation of Early Adiposity
- 2020
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 69:12, s. 2806-2818
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Tidskriftsartikel (refereegranskat)abstract
- Leptin influences food intake by informing the brain about the status of body fat stores. Rare LEP mutations associated with congenital leptin deficiency cause severe early-onset obesity that can be mitigated by administering leptin. However, the role of genetic regulation of leptin in polygenic obesity remains poorly understood. We performed an exome-based analysis in up to 57,232 individuals of diverse ancestries to identify genetic variants that influence adiposity-adjusted leptin concentrations. We identify five novel variants, including four missense variants, in LEP, ZNF800, KLHL31, and ACTL9, and one intergenic variant near KLF14. The missense variant Val94Met (rs17151919) in LEP was common in individuals of African ancestry only, and its association with lower leptin concentrations was specific to this ancestry (P = 2 × 10-16, n = 3,901). Using in vitro analyses, we show that the Met94 allele decreases leptin secretion. We also show that the Met94 allele is associated with higher BMI in young African-ancestry children but not in adults, suggesting that leptin regulates early adiposity.
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| 2. |
- Bjurström, Henrik, et al.
(författare)
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Unburned carbon in combustion residues from solid biofuels
- 2014
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 117:Part A, s. 890-899
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Tidskriftsartikel (refereegranskat)abstract
- Unburned carbon (UC) in 21 combustion residues from solid biofuels has been examined using several methods of analysis (including LOI and TOC) as well as micro-Raman spectroscopy. The concentration of unburned carbon in the residues varied over an order of magnitude and in several samples accounted for about 10% of the ash mass. It was observed that TOC had a poor correlation to organic carbon, especially for fly ashes. LOI at all tested temperatures showed a better correlation than TOC to the organic carbon content, whereas the TOC is better correlated to elemental carbon. LOI550 gave a larger variation and a less complete mobilisation of unburned carbon than LOI at 750 or 975 °C did, but at the highest temperature metal oxidation was notably affecting the mass balance to the extent that some samples gained mass. For this reason, and of the temperatures tested, LOI750 seem to be the most stable indicator for organic remains in the incineration residuals. Most of the unburned carbon is elemental, and only slowly degradable, so the potential emissions of organic compounds from ashes should not be assessed by using a TOC test. The structure of the detected elemental carbon in UC is similar to that of activated carbon, which indicates a potentially large specific surface. This should be borne in mind when assessing the environmental impact of using ash for different purposes, including use as a construction material. Field studies are needed to verify the actual impact as it may depend on environmental conditions.
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| 3. |
- Arm, Maria, et al.
(författare)
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Pulp mill fly ash for stabilization of low-volume unpaved forest roads — field performance
- 2014
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Ingår i: Canadian journal of civil engineering (Print). - : Canadian Science Publishing. - 0315-1468 .- 1208-6029. ; 41:11, s. 955-963
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Tidskriftsartikel (refereegranskat)abstract
- Increased temperatures and rainfalls will give more settlements and less bearing capacity in gravel roads, which will have implications for the forestry. Pulp mill fly ash without additives was used for stabilizing the road base of a low-volume gravel road. A two-year monitoring of the road was conducted, including measurements of achieved ash content, density, water infiltration capacity, and load bearing capacity. The results showed that the ash-stabilized sections performed better than conventionally upgraded sections and also achieved increased bearing capacity over time. Hydration of the fly ash increased the stiffness and decreased the permeability of the road base. The differences were more pronounced during spring thaw. Best performance was achieved in the section with thicker ash stabilized layer.
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| 4. |
- Vestin, Jenny, et al.
(författare)
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Biofuel ash in road stabilization : Lessons learned from six years of field testing
- 2018
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Ingår i: Transportation Geotechnics. - : Elsevier. - 2214-3912. ; 14, s. 146-156
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Tidskriftsartikel (refereegranskat)abstract
- In 2009, pulp mill fly ash was used for stabilizing the road base of a low-volume gravel road. Six years after stabilization, a two-year monitoring program and a complementary study were conducted to study the environmental and technical properties of the road and road material. Environmental properties were studied through chemical analysis of road samples by X-ray diffraction (XRF), inductively coupled plasma (ICP) technique and colorimetric techniques. The strength development was studied by falling weight deflectometer (FWD) and compressive strength tests. Potassium (K) and sulphate sulfur (SO4-S) concentrations in road material decreased by 40 and 55%, respectively during this time. Absolute concentrations of most trace elements increased. Leaching of chloride (Cl) salts from road samples decreased with time, while leaching of magnesium (Mg) and calcium (Ca) increased. Leaching of trace elements was below 0.5 mg/kg at all sampling occasions. The bearing capacity increased by 30-50%, and the infiltration capacity decreased compared to a reference section. The results showed that the ash-stabilized sections performed better than conventionally upgraded sections and achieved increased bearing capacity over time. Since the acid neutralizing capacity of the stabilized layer was high and lumps of unreacted ash were still left in the road, it was concluded that the ash material could be utilized once more in a potential end-of-life road recycling.
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