| 1. |
- Bechshoft, Thea, et al.
(författare)
-
Developing a new research tool for use in free-ranging cetaceans : recovering cortisol from harbour porpoise skin
- 2015
-
Ingår i: Conservation Physiology. - 2051-1434. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- We developed a chemical analytical procedure for sampling, extracting and determining epidermal skin cortisol concentrations (SCCs) in the harbour porpoise (Phocoena phocoena) using gas chromatography–tandem mass spectrometry. In brief, this involved a pressurized liquid extraction with a two-step solid-phase clean-up. A derivatization step was conducted prior to detection. To evaluate the new assay, cortisol was analysed in three different sample types obtained from four harbour porpoises: skin plates, dorsal fin skin plugs (with and without lidocaine) and epidermal scrapes. Skin cortisol concentrations could be measured using the new assay in the majority of the tested skin samples down to a minimal sample size of 49 mg dry weight (dw). Water content ranged from 10 to 46% in the plug samples, which had SCCs from 2.1 to 77.7 ng/g dw. Epidermal scrape samples had the highest water content (83–87%) and lower SCCs (0.6–15 ng/g dw), while the skin plates had intermediate water contents (60–66%) and SCCs of 2.6–13.0 ng/g dw. SCC was slightly higher in plugs with lidocaine than without (average values of 41 and 33 ng/g dw, respectively). Substantial within-individual variations in cortisol concentrations are also common in other matrices such as blood and hair. Some important factors behind this variation could be e.g. the animal's sex, age, body condition, reproductive stage, and the body region sampled, as well as season, moulting cycles and water temperature. Clearly, more research into SCCs is required. The findings described here represent the first critical steps towards using epidermal skin cell samples to assess chronic stress levels in cetaceans and the development of a widely applicable health-assessment tool in these species.
|
|
| 2. |
- Bechshoft, Thea, et al.
(författare)
-
Developing a new research tool for use in free-ranging cetaceans : recovering cortisol from harbour porpoise skin
- 2015
-
Ingår i: Conservation Physiology. - : Oxford University Press. - 2051-1434. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- We developed a chemical analytical procedure for sampling, extracting and determining epidermal skin cortisol concentrations (SCCs) in the harbour porpoise (Phocoena phocoena) using gas chromatography–tandem mass spectrometry. In brief, this involved a pressurized liquid extraction with a two-step solid-phase clean-up. A derivatization step was conducted prior to detection. To evaluate the new assay, cortisol was analysed in three different sample types obtained from four harbour porpoises: skin plates, dorsal fin skin plugs (with and without lidocaine) and epidermal scrapes. Skin cortisol concentrations could be measured using the new assay in the majority of the tested skin samples down to a minimal sample size of 49 mg dry weight (dw). Water content ranged from 10 to 46% in the plug samples, which had SCCs from 2.1 to 77.7 ng/g dw. Epidermal scrape samples had the highest water content (83–87%) and lower SCCs (0.6–15 ng/g dw), while the skin plates had intermediate water contents (60–66%) and SCCs of 2.6–13.0 ng/g dw. SCC was slightly higher in plugs with lidocaine than without (average values of 41 and 33 ng/g dw, respectively). Substantial within-individual variations in cortisol concentrations are also common in other matrices such as blood and hair. Some important factors behind this variation could be e.g. the animal's sex, age, body condition, reproductive stage, and the body region sampled, as well as season, moulting cycles and water temperature. Clearly, more research into SCCs is required. The findings described here represent the first critical steps towards using epidermal skin cell samples to assess chronic stress levels in cetaceans and the development of a widely applicable health-assessment tool in these species.
|
|
| 3. |
- Lichtenberg, Elinor M., et al.
(författare)
-
A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes
- 2017
-
Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 23:11, s. 4946-4957
-
Tidskriftsartikel (refereegranskat)abstract
- Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in-field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in-field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.
|
|
| 4. |
- Weisser, Johan J., et al.
(författare)
-
A novel method for analysing key corticosteroids in polar bear (Ursus maritimus) hair using liquid chromatography tandem mass spectrometry
- 2016
-
Ingår i: Journal of chromatography. B. - 1570-0232 .- 1873-376X. ; 1017, s. 45-51
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents the development and evaluation of a methodology for extraction, clean-up and analysis of three key corticosteroids (aldosterone, cortisol and corticosterone) in polar bear hair. Such a methodology can be used to monitor stress biomarkers in polar bears and may provide as a useful tool for long-term and retrospective information. We developed a combined pressurized liquid extraction (PLE)-solid phase extraction (SPE) procedure for corticosteroid extraction and clean-up followed by high pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis. This procedure allows for the simultaneous determination of multiple steroids, which is in contrast to previous polar bear studies based on ELISA techniques. Absolute method recoveries were 81%, 75% and 60% for cortisol, corticosterone and aldosterone, respectively. We applied the developed method on a hair sample pooled from four East Greenland polar bears. Herein cortisol and corticosterone were successfully determined in levels of 0.32 +/- 0.02 ng/g hair and 0.13 +/- 0.02 ng/g hair, respectively. Aldosterone was below limit of detection (LOD<0.17 ng/g). The cortisol hair concentration found in these East Greenland polar bears was consistent with cortisol levels previously determined in the Southern Hudson Bay and James Bay in Canada using ELISA kits. (C) 2016 Elsevier B.V. All rights reserved.
|
|
| 5. |
- Weisser, Johan J., et al.
(författare)
-
A novel method for analysing key corticosteroids in polar bear (Ursus maritimus) hair using liquid chromatography tandem mass spectrometry
- 2016
-
Ingår i: Journal of chromatography. B. - : Elsevier BV. - 1570-0232. ; 1017, s. 45-51
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents the development and evaluation of a methodology for extraction, clean-up and analysis of three key corticosteroids (aldosterone, cortisol and corticosterone) in polar bear hair. Such a methodology can be used to monitor stress biomarkers in polar bears and may provide as a useful tool for long-term and retrospective information. We developed a combined pressurized liquid extraction (PLE)-solid phase extraction (SPE) procedure for corticosteroid extraction and clean-up followed by high pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis. This procedure allows for the simultaneous determination of multiple steroids, which is in contrast to previous polar bear studies based on ELISA techniques. Absolute method recoveries were 81%, 75% and 60% for cortisol, corticosterone and aldosterone, respectively. We applied the developed method on a hair sample pooled from four East Greenland polar bears. Herein cortisol and corticosterone were successfully determined in levels of 0.32 +/- 0.02 ng/g hair and 0.13 +/- 0.02 ng/g hair, respectively. Aldosterone was below limit of detection (LOD<0.17 ng/g). The cortisol hair concentration found in these East Greenland polar bears was consistent with cortisol levels previously determined in the Southern Hudson Bay and James Bay in Canada using ELISA kits. (C) 2016 Elsevier B.V. All rights reserved.
|
|
