| 1. |
|
|
| 2. |
|
|
| 3. |
- Pumpanen, J, et al.
(författare)
-
Comparison of different chamber techniques for measuring soil CO2 efflux
- 2004
-
Ingår i: Agricultural and Forest Meteorology. - : Elsevier BV. - 1873-2240 .- 0168-1923. ; 123:3-4, s. 159-176
-
Tidskriftsartikel (refereegranskat)abstract
- Twenty chambers for measurement of soil CO2 efflux were compared against known CO2 fluxes ranging from 0.32 to 10.01 mumol CO2 m(-2) s(-1) and generated by a specially developed calibration tank. Chambers were tested on fine and coarse homogeneous quartz sand with particle sizes of 0.05-0.2 and 0.6 mm, respectively. The effect of soil moisture on chamber measurements was tested by wetting the fine quartz sand to about 25% volumetric water content. Non-steady-state through-flow chambers either underestimated or overestimated fluxes from -21 to +33% depending on the type of chamber and the method of mixing air within the chamber's headspace. However, when results of all systems tested were averaged, fluxes were within 4% of references. Non-steady-state non-through-flow chambers underestimated or overestimated fluxes from -35 to +6%. On average, the underestimation was about 13-14% on fine sand and 4% on coarse sand. When the length of the measurement period was increased, the underestimation increased due to the rising concentration within the chamber headspace, which reduced the diffusion gradient within the soil. Steady-state through-flow chambers worked almost equally well in all sand types used in this study. They overestimated the fluxes on average by 2-4%. Overall, the reliability of the chambers was not related to the measurement principle per se. Even the same chambers, with different collar designs, showed highly variable results. The mixing of air within the chamber can be a major source of error. Excessive turbulence inside the chamber can cause mass flow of CO2 from the soil into the chamber. The chamber headspace concentration also affects the flux by altering the concentration gradient between the soil and the chamber.
|
|
| 4. |
|
|
| 5. |
- Viskari, Hanna, et al.
(författare)
-
Relationship between the Incidence of Type 1 Diabetes and Enterovirus Infections in Different European Populations : Results from the EPIVIR Project
- 2004
-
Ingår i: Journal of Medical Virology. - : John Wiley & Sons. - 0146-6615 .- 1096-9071. ; 72:4, s. 610-617
-
Tidskriftsartikel (refereegranskat)abstract
- The incidence of type 1 diabetes varies markedly between countries. As enterovirus infections have been linked to type 1 diabetes, we determined whether this variation correlates with the frequency of enterovirus infections in different Caucasian populations in Europe. Enterovirus antibodies were examined in the background population (1-year-old and 10-14-year-old children) in seven countries with either exceptionally high (Finland and Sweden) or low/intermediate incidence of diabetes (Estonia, Germany, Hungary, Lithuania, Russia) using EIA and neutralisation assays. Enterovirus antibodies were less frequent in countries with high diabetes incidence compared to countries with low diabetes incidence (P < 0.001). This suggests that enterovirus infections are not particularly common in countries with high diabetes incidence. In contrast, there seems to be an inverse correlation between the incidence of type 1 diabetes and enterovirus infections in the background population, which is in line with the previously proposed polio hypothesis according to which the complications of enterovirus infections become more common in an environment with a decreased rate of infections. © 2004 Wiley-Liss, Inc.
|
|
| 6. |
- Ziegler, Friederike, et al.
(författare)
-
Life cycle assessment of frozen cod fillets including fishery-specific environmental impacts
- 2003
-
Ingår i: International Journal of Life Cycle Assessment. - 0948-3349 .- 1614-7502. ; 8:1, s. 39-47
-
Tidskriftsartikel (refereegranskat)abstract
- Goal, Scope and Background. The purpose of the present study was to perform an environmental assessment for the entire life cycle of a seafood product and to include fishery-specific types of environmental impact in inventory and assessment. Environmental data for a frozen block of cod fillets was collected and used for a Life Cycle Assessment, including the fishery-specific environmental aspects seafloor use and biological extraction of target, by-catch and discard species. The fishery takes place in the Baltic Sea where cod is mainly fished by benthic trawls and gillnets. Methods. The functional unit was a consumer package of frozen cod fillets (400 g) reaching the household. Data was gathered from fishermen, fishery statistics, databases, companies and literature. Fishery-specific issues like the impact on stocks of the target and by-catch species, seafloor impact and discarding were quantified in relation to the functional unit and qualitative impact assessment of these aspects was included. Results. Findings include the fact that all environmental impact categories assessed (Global Warming Potential, Eutrophication Potential, Acidification Potential, Photochemical Ozone Creation Potential and Aquatic Ecotoxiciy) are dominated by the fishery. Around 700 m(2) of seafloor are swept by trawls and around 50 g of under-sized cod and other marine species are discarded per functional unit. The phases contributing most to total environmental impact following fishery were transports and preparation in the household. The process industry and municipal sewage treatment cause considerable amounts of eutrophying emissions. Conclusions. Conclusions are that there are considerable options for improvement of the environmental performance of the seafood production chain. In the fishery, the most important environmental measure is to fish sustainably managed stocks. Speed optimisation, increased use of less energy-intensive fishing gear and improved engine and fuel technology are technical measures that would considerably decrease resource use and environmental impact caused by fishery. Due to the importance of fishery for the overall results, the most important environmental improvement option after landing is to maintain high quality and minimise product losses. Recommendations and Outlook. The need for good baseline data concerning resource use and marine environmental impact of fisheries in order to perform environmental assessment of seafood products was demonstrated. LCA was shown to be a valuable tool for such assessments, which in the future could be used to improve the environmental performance of the seafood production chain or in the development of criteria of eco-labelling of seafood products originating in capture fisheries.
|
|
