| 1. |
|
|
| 2. |
- Broström, Anna, et al.
(författare)
-
Pollen productivity estimates of key European plant taxa for quantitative reconstruction of past vegetation : a review
- 2008
-
Ingår i: Vegetation History and Archaeobotany. - : Springer Science and Business Media LLC. - 0939-6314 .- 1617-6278. ; 17:5, s. 461-478
-
Tidskriftsartikel (refereegranskat)abstract
- Information on the spatial distribution of past vegetation on local, regional and global scales is increasingly used within climate modelling, nature conservancy and archaeology. It is possible to obtain such information from fossil pollen records in lakes and bogs using the landscape reconstruction algorithm (LRA) and its two models, REVEALS and LOVE. These models assume that reliable pollen productivity estimates (PPEs) are available for the plant taxa involved in the quantitative reconstructions of past vegetation, and that PPEs are constant through time. This paper presents and discusses the PPEs for 15 tree and 18 herb taxa obtained in nine study areas of Europe. Observed differences in PPEs between regions may be explained by methodological issues and environmental variables, of which climate and related factors such as reproduction strategies and growth forms appear to be the most important. An evaluation of the PPEs at hand so far suggests that they can be used in modelling applications and quantitative reconstructions of past vegetation, provided that consideration of past environmental variability within the region is used to inform selection of PPEs, and bearing in mind that PPEs might have changed through time as a response to climate change. Application of a range of possible PPEs will allow a better evaluation of the results.
|
|
| 3. |
- Carlsson, Henrik, et al.
(författare)
-
LC–MS/MS Screening Strategy for Unknown Adducts to N-Terminal Valine in Hemoglobin Applied to Smokers and Nonsmokers
- 2014
-
Ingår i: Chemical Research in Toxicology. - : American Chemical Society (ACS). - 0893-228X .- 1520-5010. ; 27:12, s. 2062-2070
-
Tidskriftsartikel (refereegranskat)abstract
- Electrophilically reactive compounds have the ability to form adducts with nucleophilic sites in DNA and proteins, constituting a risk for toxic effects. Mass spectrometric detection of adducts to N-terminal valine in hemoglobin (Hb) after detachment by modified Edman degradation procedures is one approach for in vivo monitoring of exposure to electrophilic compounds/metabolites. So far, applications have been limited to one or a few selected reactive species, such as acrylamide and its metabolite glycidamide. This article presents a novel screening strategy for unknown Hb adducts to be used as a basis for an adductomic approach. The method is based on a modified Edman procedure, FIRE, specifically developed for LC-MS/MS analysis of N-terminal valine adducts in Hb detached as fluorescein thiohydantoin (FTH) derivatives. The aim is to detect and identify a priori unknown Hb adducts in human blood samples. Screening of valine adducts was performed by stepwise scanning of precursor ions in small mass increments, monitoring four fragments common for the FTH derivative of valine with different N-substitutions in the multiple-reaction mode, covering a mass range of 135 Da (m/z 503-638). Samples from six smokers and six nonsmokers were analyzed. Control experiments were performed to compare these results with known adducts and to check for artifactual formation of adducts. In all samples of smokers and nonsmokers, seven adducts were identified, of which six have previously been studied. Nineteen unknown adducts were observed, and 14 of those exhibited fragmentation patterns similar to earlier studied FTH derivatives of adducts to valine. Identification of the unknown adducts will be the focus of future work. The presented methodology is a promising screening tool using Hb adducts to indicate exposure to potentially toxic electrophilic compounds and metabolites.
|
|
| 4. |
|
|
| 5. |
- de Jong, Johnny, et al.
(författare)
-
Consequences of an increased extraction of forest biofuel in Sweden : a synthesis from the biofuel research programme 2007-2011
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- EXECUTIVE SUMMARY.This report summarizes the state of knowledge with respect to possibilities for increasing the extraction of forest fuel in Sweden and the consequences of such increases on soil, water and biodiversity. It is based, above all, on research carried out within the Swedish Energy Agency’s research programme “the Bioenergy Feedstock Programme” (2007-2011), as well as on other, related projects financed by the Energy Agency. The goal of the study was to investigate and highlight1. New knowledge emerged from the Bioenergy Feedstock Programme;2. The link between research results and national environmental objectives and forestry guidelines;3. What questions remain to be answered in order to allow for a long-term and sustainable production and use of forest fuels.The result shows that there is a considerable potential for increasing forest fuel extraction without decreasing possibilities of achieving other societal, environmental and forest production objectives. The current extraction level of approximately 50 PJ can be increased to 87 PJ, at least. Branches and tops are the least problematic, while some questions remain regarding the consequences of stump extraction. Nevertheless, limited stump extraction should be possible. This increased extraction is linked to a number of conditions which must be fulfilled in order for negative effects to be avoided, i.e.:1. That the general environmental considerations in forestry are not negatively affected.2. That extracted branches, tops and stumps mainly comes from conifers.3. That compensation for loss of base cations by means of ash recycling is done where needed, using good-quality ash.4. That it is possible to limit soil damage as felling residues and stumps, when harvested, cannot be used to reinforce the strip roads (extraction of branches, tops and stumps can only be done on land with good load-bearing capacity).5. That extraction is not done near woodland key habitats and nature reserves, where an increase in the amount of deadwood exposed to sunlight is likely to be more beneficial for biodiversity than if it is left elsewhere in a managed forest landscape
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Gaillard, Marie-José, 1953-, et al.
(författare)
-
Holocene land-cover reconstructions for studies on land cover-climate feedbacks
- 2010
-
Ingår i: Climate of the Past. - : Copernicus GmbH. - 1814-9324 .- 1814-9332. ; 6, s. 483-499
-
Tidskriftsartikel (refereegranskat)abstract
- The major objectives of this paper are: (1) to review the pros and cons of the scenarios of past anthropogenic land cover change (ALCC) developed during the last ten years, (2) to discuss issues related to pollen-based reconstruction of the past land-cover and introduce a new method, REVEALS (Regional Estimates of VEgetation Abundance from Large Sites), to infer long-term records of past land-cover from pollen data, (3) to present a new project (LANDCLIM: LAND cover – CLIMate interactions in NW Europe during the Holocene) currently underway, and show preliminary results of REVEALS reconstructions of the regional land-cover in the Czech Republic for five selected time windows of the Holocene, and (4) to discuss the implications and future directions in climate and vegetation/land-cover modeling, and in the assessment of the effects of human-induced changes in land-cover on the regional climate through altered feedbacks. The existing ALCC scenarios show large discrepancies between them, and few cover time periods older than AD 800. When these scenarios are used to assess the impact of human land-use on climate, contrasting results are obtained. It emphasizes the need for methods such as the REVEALS model-based land-cover reconstructions. They might help to fine-tune descriptions of past land-cover and lead to a better understanding of how long-term changes in ALCC might have influenced climate. The REVEALS model is demonstrated to provide better estimates of the regional vegetation/landcover changes than the traditional use of pollen percentages. This will achieve a robust assessment of land cover at regional- to continental-spatial scale throughout the Holocene. We present maps of REVEALS estimates for the percentage cover of 10 plant functional types (PFTs) at 200 BP and 6000 BP, and of the two open-land PFTs “grassland” and “agricultural land” at five time-windows from 6000 BP to recent time. The LANDCLIM results are expected to provide crucial data to reassess ALCC estimates for a better understanding of the land suface-atmosphere interactions.
|
|
| 10. |
- Gaillard, Marie-Jose, et al.
(författare)
-
The use of modelling and simulation approach in reconstructing past landscapes from fossil pollen data: a review and results from the POLLANDCAL network
- 2008
-
Ingår i: Vegetation History and Archaeobotany. - : Springer Science and Business Media LLC. - 0939-6314 .- 1617-6278. ; 17:5, s. 419-443
-
Tidskriftsartikel (refereegranskat)abstract
- Information on past land cover in terms of absolute areas of different landscape units (forest, open land, pasture land, cultivated land, etc.) at local to regional scales is needed to test hypotheses and answer questions related to climate change (e.g. feedbacks effects of land-cover change), archaeological research, and nature conservancy (e.g. management strategy). The palaeoecological technique best suited to achieve quantitative reconstruction of past vegetation is pollen analysis. A simulation approach developed by Sugita (the computer model POLLSCAPE) which uses models based on the theory of pollen analysis is presented together with examples of application. POLLSCAPE has been adopted as the central tool for POLLANDCAL (POLlen/LANdscape CALibration), an international research network focusing on this topic. The theory behind models of the pollen-vegetation relationship and POLLSCAPE is reviewed. The two model outputs which receive greatest attention in this paper are the relevant source area of pollen (RSAP) and pollen loading in mires and lakes. Six examples of application of POLLSCAPE are presented, each of which explores a possible use of the POLLANDCAL tools and a means of validating or evaluating the models with empirical data. The landscape and vegetation factors influencing the size of the RSAP, the importance of pollen productivity estimates (PPEs) for the model outputs, the detection of small and rare patches of plant taxa in pollen records, and quantitative reconstructions of past vegetation and landscapes are discussed on the basis of these examples. The simulation approach is seen to be useful both for exploring different vegetation/landscape scenarios and for refuting hypotheses.
|
|
