| 1. |
- Jönsson, K. Ingemar, 1959-, et al.
(författare)
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Tolerance to gamma radiation in the marine heterotardigrade, Echiniscoides sigismundi
- 2016
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Ingår i: PLOS ONE. - 1932-6203. ; 11:12
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades belong to the most radiation tolerant animals on Earth, as documented by a number of studies using both low-LET and high-LET ionizing radiation. Previous studies have focused on semi-terrestrial species, which are also very tolerant to desiccation. The predominant view on the reason for the high radiation tolerance among these semi-terrestrial species is that it relies on molecular mechanisms that evolved as adaptations for surviving dehydration. In this study we report the first study on radiation tolerance in a marine tardigrade, Echiniscoides sigismundi. Adult specimens in the hydrated active state were exposed to doses of gamma radiation from 100 to 5000 Gy. The results showed little effect of radiation at 100 and 500 Gy but a clear decline in activity at 1000 Gy and higher. The highest dose survived was 4000 Gy, at which ca. 8% of the tardigrades were active 7 days after irradiation. LD50 in the first 7 days after irradiation was in the range of 1100±1600 Gy. Compared to previous studies on radiation tolerance in semi-terrestrial and limnic tardigrades, Echiniscoides sigismundi seems to have a lower tolerance. However, the species still fits into the category of tardigrades that have high tolerance to both desiccation and radiation, supporting the hypothesis that radiation tolerance is a by-product of adaptive mechanisms to survive desiccation. More studies on radiation tolerance in tardigrade species adapted to permanently wet conditions, both marine and freshwater, are needed to obtain a more comprehensive picture of the patterns of radiation tolerance.
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| 2. |
- Beery, Thomas H., et al.
(författare)
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Outdoor recreation and place attachment : exploring the potential of outdoor recreation within a UNESCO Biosphere Reserve
- 2017
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Ingår i: Journal of Outdoor Recreation. - 2213-0780 .- 2213-0799. ; 17, s. 54-63
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates outdoor recreation participation within a multifunctional landscape, a UNESCO Man and Biosphere Reserve. The reserve, the Kristianstad Vattenrike located in southern Sweden, has made a deliberate effort to make the experience of biodiversity possible for residents and visitors. Recreation is a keypart of the biodiversity conservation effort in the area, represented by the infrastructure of the Kristianstad Vattenrike's 21 visitor sites. Given the biosphere reserve context, this study investigates the question of whether there is a relationship between outdoor recreation participation and place attachment. Survey data was collected using concurrent application of multiple sampling strategies including both probability and purposive sampling of local adult residents of the biosphere area. Quantitative analysis showed a significant positive relationship between the level of outdoor recreation participation and place attachment. Qualitative data supported this relationship with more details about place attachment within the studied area. The study confirms a relationship between place attachment and outdoor recreation and provides insight into how the biosphere reserve context supports this relationship. The results of this study show that significant biodiversity management in close conjunction with outdoor recreational opportunity can be achieved and provides opportunities for human engagement and experience of biodiversity.Management Implications: This research can help managers design recreational settings that support biodiversity conservation goals. Our research found that:• A leading motivation for outdoor recreation participation is nature experience and this motivation can be used by managers to highlight a biodiversity conservation interpretive message in the design of outdoor recreation infrastructure.• Providing proximate access to nature based outdoor recreation, to support deliberate and direct experience of biodiversity, is an important component of engaging the public in biodiversity conservation.• Recreation proximity alone will not create public engagement in biodiversity conservation. However,proximity as a part of a deliberate institutional design including biodiversity conservation, sustainable development, and logistic support for research and monitoring may be critical for public engagement.
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| 3. |
- Berg, Johan, et al.
(författare)
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Äta insekter : finns det några hälsorisker?
- 2019
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Ingår i: Nutritionsfakta. ; december
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- En tidigare publicerad artikel i Nutritionsfakta har visat på hälso- och hållbarhetsfördelar med att äta insekter. Finns det då några hälsorisker med att äta insekter? När det gäller kemiska risker är dessa små, förutsatt att producenten har kontroll på fodrets tungmetallinnehåll. Bakterier och andra mikroorganismer behöver kontrolleras noga, men inga tydliga risker finns här heller. Personer med skaldjursallergier bör dock vara försiktiga med insekter. Generellt motsvarar riskerna de som gäller för andra animaliska livsmedel, och samma typ av kontrollprogram bör finnas. Dock behövs mer forskning inom området. Kött från nöt, svin och fjäderfä har studerats under lång tid; det är dags att låta forskningen kring insekter som mat börja ta igen det försprånget.
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| 4. |
- Betts, Bruce H, et al.
(författare)
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Phobos LIFE (Living Interplanetary Flight Experiment).
- 2019
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Ingår i: Astrobiology. - 1531-1074 .- 1557-8070.
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Tidskriftsartikel (refereegranskat)abstract
- The Planetary Society's Phobos Living Interplanetary Flight Experiment (Phobos LIFE) flew in the sample return capsule of the Russian Federal Space Agency's Phobos Grunt mission and was to have been a test of one aspect of the hypothesis that life can move between nearby planets within ejected rocks. Although the Phobos Grunt mission failed, we present here the scientific and engineering design and motivation of the Phobos LIFE experiment to assist with the scientific and engineering design of similar future experiments. Phobos LIFE flew selected organisms in a simulated meteoroid. The 34-month voyage would have been the first such test to occur in the high-radiation environment outside the protection of Earth's magnetosphere for more than a few days. The patented Phobos LIFE "biomodule" is an 88 g cylinder consisting of a titanium outer shell, several types of redundant seals, and 31 individual Delrin sample containers. Phobos LIFE contained 10 different organisms, representing all three domains of life, and one soil sample. The organisms are all very well characterized, most with sequenced genomes. Most are extremophiles, and most have flown in low Earth orbit. Upon return from space, the health and characteristics of organisms were to have been compared with controls that remained on Earth and have not yet been opened.
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| 5. |
- Czarnezki, Jason J., et al.
(författare)
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Crafting next generation eco-label policy
- 2018
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Ingår i: Environmental Law. ; 48:3, s. 409-452
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Eco-labels present a promising policy tool in the effort to achieve sustainable consumption. Many questions remain, however, about the extent to which eco-labels can contribute to sustainability efforts and how to maximize their effectiveness. This Article deploys research from evolutionary psychology, behavioral law and economics, and norm theory to offer specific insights for the design and implementation of eco-labels to enhance their influence on sustainable consumer choice. Notably, this research suggests possibilities for ecolabels to shape or expand consumer preferences for green goods, and thereby enhance eco-label influence on consumer behavior by extending it beyond eco-minded consumers. We suggest that public exposure of the label (so that people see it) and the exposure of the purchasing behavior (so that other people can see that you have bought the product) are key elements to the success of eco-labels—the social context around product purchasing may be as important as the ecolabel itself. We recommend that behavioral insights be used to improve eco-labeling as traditionally understood by incorporating knowledge about behavioral tendencies into label design so as to allow for more accurate matching of consumers’ preexisting environmental preferences to eco-labeled goods, and develop next-generation ecolabeling policy with the potential to significantly expand the market for eco-labeled goods. Specifically, 1) Eco-labels could be purposefully designed and implemented to attract consumers motivated by social norms; 2) Eco-labels could appeal to a wider range of abstract norm alternate more broadly or locally accepted and strong abstract that are stronger and/or more broadly accepted or locally-salient; and 3) Ecolabels could highlight private, near and near-term benefits.
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| 6. |
- Czernekova, Michaela, et al.
(författare)
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A comparative ultrastructure study of storage cells in the eutardigrade Richtersius coronifer in the hydrated state and after desiccation and heating stress
- 2018
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Ingår i: PLOS ONE. - 1932-6203. ; 13:8
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades represent an invertebrate phylum with no circulatory or respiratory system.Their body cavity is filled with free storage cells of the coelomocyte-type, which are responsible for important physiological functions. We report a study comparing the ultrastructure of storage cells in anhydrobiotic and hydrated specimens of the eutardigrade Richtersius coronifer. We also analysed the effect of temperature stress on storage cell structure. Firstly, we verified two types of ultrastructurally different storage cells, which differ in cellular organelle complexity, amount and content of reserve material and connection to oogenetic stage. Type I cells were found to differ ultrastructurally depending on the oogenetic stage of the animal. The main function of these cells is energy storage. Storage cells of Type I were also observed in the single male that was found among the analysed specimens. The second cell type, Type II, found only in females, represents young undifferentiated cells, possibly stem cells. The two types of cells also differ with respect to the presence of nucleolar vacuoles,which are related to oogenetic stages and to changes in nucleolic activity during oogenesis. Secondly, this study revealed that storage cells are not ultrastructurally affected by six months of desiccation or by heating following this desiccation period. However, heating of the desiccated animals (tuns) tended to reduce animal survival, indicating that longterm desiccation makes these animals more vulnerable to heat stress. We confirmed the degradative pathways during the rehydration process after desiccation and heat stress. Our study is the first to document two ultrastructurally different types of storage cells in tardigrades and reveals new perspectives for further studies of tardigrade storage cells.
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| 7. |
- Czernekova, Michaela, et al.
(författare)
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Evaluation of extraction methods for quantitative analysis of tardigrade populations in soil and leaf litter
- 2018
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Ingår i: Pedobiologia. - : Elsevier. - 0031-4056 .- 1873-1511. ; 70, s. 1-5
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Tidskriftsartikel (refereegranskat)abstract
- Accurate quantitative analysis of soil tardigrades depends on a relevant extraction method. Over the years, a number of different methods have been used, but the efficiency of these methods has rarely been evaluated for soil and leaf litter tardigrades. Four methods of extraction were compared in this study: the light-cooling (L-C) extractor, the high-gradient (H-G), Baermann extractor, the non-gradient (N-G) Baermann extractor and sieves.The results indicate that light and temperature are significant factors influencing tardigrade extraction. The L-C and H-G extractors were more effective than sieves for all substrate categories. These extraction methods (L-C and H-G) therefore seem to be appropriate for quantitative studies of soil and leaf litter tardigrades.
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| 8. |
- Czernekova, Michaela, et al.
(författare)
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Experimentally induced repeated anhydrobiosis in the Eutardigrade Richtersius coronifer
- 2016
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Ingår i: PLOS ONE. - 1932-6203. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades represent one of the main animal groups with anhydrobiotic capacity at any stage of their life cycle. The ability of tardigrades to survive repeated cycles of anhydrobiosis has rarely been studied but is of interest to understand the factors constraining anhydrobiotic survival. The main objective of this study was to investigate the patterns of survival of the eutardigrade Richtersius coronifer under repeated cycles of desiccation, and the potential effect of repeated desiccation on size, shape and number of storage cells. We also analyzed potential change in body size, gut content and frequency of mitotic storage cells. Specimens were kept under non-cultured conditions and desiccated under controlled relative humidity. After each desiccation cycle 10 specimens were selected for analysis of morphometric characteristics and mitosis. The study demonstrates that tardigrades may survive up to 6 repeated desiccations, with declining survival rates with increased numberof desiccations. We found a significantly higher proportion of animals that were unable to contract properly into a tun stage during the desiccation process at the 5th and 6th desiccations. Also total number of storage cells declined at the 5th and 6th desiccations, while no effect on storage cell size was observed. The frequency of mitotic storage cells tended to decline with higher number of desiccation cycles. Our study shows that the number of consecutive cycles of anhydrobiosis that R. coronifer may undergo is limited, with increased inability for tun formation and energetic constraints as possible causal factors.
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| 9. |
- Czernekova, Michaela, et al.
(författare)
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Mitosis in storage cells of the eutardigrade Richtersius coronifer
- 2016
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Ingår i: Zoological Journal of the Linnean Society. - 0024-4082 .- 1096-3642. ; 178:4, s. 888-896
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Tidskriftsartikel (refereegranskat)abstract
- Although tardigrades are sometimes reported as eutelic animals, mitosis has been reported in several somatic tissues of adult eutardigrades. The occurrence of cell division in storage cells is particularly interesting in light of the important role that these cells play in the physiology of tardigrades. We present data on the occurrence of mitosis in storage cells of the eutardigrade Richtersius coronifer (Richters, 1903), and analyse mitotic cells in relation to different body characteristics, including egg development stage, moulting, gut content, body length, number and size of oocytes, and shape and size of the storage cells. Mitosis was present in ~20% of all animals, and was more frequent in juveniles than in adults. The proportion of cells with mitosis (‘mitotic index’) was low: 0.76% in juveniles and 1.47% in adults. In juveniles, none of the measured phenotypic characters had significant predictive power for mitosis, whereas in adult animals in moult or in late egg developmental or post-laying stage were more likely to have mitotic storage cells. The association with the later part of the moulting process was particularly strong. The low mitotic index and the strong association with moulting suggests that mitosis in storage cells may be connected with somatic growth rather than cell renewal, and that the purpose of cell division may relate to a need of more cells to support the enlarged body after moulting. However, the specific life cycle of tardigrades, where energy intake and depletion, egg development, and moulting is highly intertwined and synchronized, make conclusions about the functional role of mitosis in storage cells difficult, however, and more studies are needed to reveal the mechanisms inducing mitosis in these interesting cells.
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| 10. |
- Czernekova, Michaela, et al.
(författare)
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Primary Culture of Tardigrade Storage Cells from Richtersius coronifer Richters, 1903
- 2016
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Konferensbidrag (refereegranskat)abstract
- Coelomocytes are macrophage-like cells in the body cavity or the coelomic spaces of many invertebrates and play major roles in their physiology and immunology. Their structure, function and diversity, however, is still poorly understood.Tardigrades are micrometazoans inhabiting a wide variety of environments and with an ability to survive extreme conditions. Coelomocytes (“storage cells”) represent an important part of tardigrade physiology, storing and distributing energy and possibly also having immunological functions. Few studies of tardigrade cell biology have been reported and neither primary nor continuous cell cultures have been established. Tardigrades are normally found and also cultured in an environment rich in microorganisms, some of which may even be of symbiotic value.In this study we have tried to establish a primary culture of storage cells in the eutardigrade Richtersius coronifer. Different cell media and concentrations of fetal bovine serum (FBS) were tested. Extracting cells from the tardigrades in an antiseptical environment is challenging since it has to be done under a microscope and contamination from the tardigrades surface is also a problem. To avoid this we tried culturing with high concentrations of antibiotics and antimycotics. We managed to keep the cells viable for up to 18 days in Grace insect medium with 10 % FBS at 20-22°C. The medium was changed every third day. 10x Antibiotic-Antimycotic and 5x of Penicillin-Streptomycin were used to minimize contamination. These concentrations reduce the bacterial abundance, but contamination with fungi was still an issue. Cell morphology evaluation was performed daily and no obvious toxic effects on the cells was observed. Cell viability and cell division were evaluated with Trypan blue staining and cell counting in a haemocytometer. The results indicate that the cells are viable and that some cell division occurs, however more studies need to be performed to confirm this. Still, this study provides the first evidence that primary cultures of storage cells from tardigrades are possible to establish, but the culturing method has to be refined to avoid contamination.
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