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- Fisher, Matthew C., et al.
(författare)
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Development and worldwide use of non-lethal, and minimal population-level impact, protocols for the isolation of amphibian chytrid fungi
- 2018
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Parasitic chytrid fungi have emerged as a significant threat to amphibian species worldwide, necessitating the development of techniques to isolate these pathogens into culture for research purposes. However, early methods of isolating chytrids from their hosts relied on killing amphibians. We modified a pre-existing protocol for isolating chytrids from infected animals to use toe clips and biopsies from toe webbing rather than euthanizing hosts, and distributed the protocol to researchers as part of the BiodivERsA project RACE; here called the RML protocol. In tandem, we developed a lethal procedure for isolating chytrids from tadpole mouthparts. Reviewing a database of use a decade after their inception, we find that these methods have been applied across 5 continents, 23 countries and in 62 amphibian species. Isolation of chytrids by the non-lethal RML protocol occured in 18% of attempts with 207 fungal isolates and three species of chytrid being recovered. Isolation of chytrids from tadpoles occured in 43% of attempts with 334 fungal isolates of one species (Batrachochytrium dendrobatidis) being recovered. Together, these methods have resulted in a significant reduction and refinement of our use of threatened amphibian species and have improved our ability to work with this group of emerging pathogens.
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| 2. |
- Hulme-Smith, Christopher, 1989-, et al.
(författare)
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A practicable and reliable test for metal powder spreadability : development of test and analysis technique
- 2023
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Ingår i: Progress in Additive Manufacturing. - : Springer Nature. - 2363-9512 .- 2363-9520. ; 8:3, s. 505-517
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Tidskriftsartikel (refereegranskat)abstract
- A crucial step in the powder bed metal additive manufacturing process is the formation of a thin layer of powder on top of the existing material. The propensity of the powder to form thin layers under the conditions used in additive manufacturing is critically important, but no test method has yet been established to measure this characteristic, which is sometimes referred to as spreadability. The current work spreads a single layer of powder using commercial equipment from the paint and food industries and derives the density of a layer of powder, which is of a similar thickness to that in additive manufacturing. Twenty-four powders from eight suppliers have been tested and the density of the layers has been measured as a function of various parameters. Twenty-two of the powders successfully form thin layers, with a density of at least 40% of each powder’s apparent density. Hall flow time did not correlate with the spread layer density, although the two powders that did not spread did not pass through the Hall funnel. The roughness of the plate onto which the powder was spread, the recoater speed, the layer thickness, particle size and aspect ratio all affect the measured layer density. Results of the new test are repeatable and reproducible. These findings can be used to develop a test for spreadability for metal powders that can be used for additive manufacturing, which will help to improve the quality of printed components.
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| 3. |
- O'Hanlon, Simon J., et al.
(författare)
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Recent Asian origin of chytrid fungi causing global amphibian declines
- 2018
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 360:6389, s. 621-
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Tidskriftsartikel (refereegranskat)abstract
- Globalized infectious diseases are causing species declines worldwide, but their source often remains elusive. We used whole-genome sequencing to solve the spatiotemporal origins of themost devastating panzootic to date, caused by the fungus Batrachochytrium dendrobatidis, a proximate driver of global amphibian declines. We traced the source of B. dendrobatidis to the Korean peninsula, where one lineage, BdASIA-1, exhibits the genetic hallmarks of an ancestral population that seeded the panzootic. We date the emergence of this pathogen to the early 20th century, coinciding with the global expansion of commercial trade in amphibians, and we show that intercontinental transmission is ongoing. Our findings point to East Asia as a geographic hotspot for B. dendrobatidis biodiversity and the original source of these lineages that now parasitize amphibians worldwide.
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| 7. |
- Angsten, G, et al.
(författare)
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Metabolic effects in neonates receiving intravenous medium-chain triglycerides
- 2002
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Ingår i: Acta Paediatrica. - 0803-5253 .- 1651-2227. ; 91:2, s. 188-197
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Tidskriftsartikel (refereegranskat)abstract
- The effects of two lipid emulsions, one with 5017( each of medium-chain and long-chain triglycerides, and a long-chain triglycerides lipid emulsion as a control, were evaluated for lipid and carnitine metabolism and respiratory quotient when given to neonates after major surgery during a short period of total parenteral nutrition. Each group included 10 neonates, and all tolerated the total parenteral nutrition well. The relative contents of linoleic acid and)alpha-linolenic acid increased in all lipid esters in plasma and adipose tissue in both groups, indicating that the content of these fatty acids is sufficient even in the medium-chain triglycerides emulsion. The serum concentration of ketones was within normal limits. Free fatty acids in plasma did not increase in either group. The total plasma carnitine concentration decreased in both groups but the distribution of free carnitine and acylcarnitine did not change. The total muscle carnitine did not change significantly but the ratio of acylcarnitine to free carnitine tended to increase in muscle in the treatment group, probably an effect of the medium-chain triglyceride supplementation. Conclusions: The two groups displayed the same fatty acid pattern in plasma and adipose tissue and the same respiratory quotient during the treatment period. Regarding carnitine status, essentially the same changes were seen in the two groups. However, discrete changes were seen in muscle tissue in the treatment group.
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| 9. |
- Angsten, G., et al.
(författare)
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Reference ranges for muscle carnitine concentration in children
- 2003
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Ingår i: Annals of Clinical Biochemistry. - : SAGE Publications. - 0004-5632 .- 1758-1001. ; 40:4, s. 406-410
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Tidskriftsartikel (refereegranskat)abstract
- Background: We investigated muscle and plasma carnitine concentrations in children to establish reference intervals for use following biopsy of skeletal muscle. Methods: The study comprised 50 children from newborns up to 14 years of age, all undergoing elective surgery. They were divided into six age groups, the youngest 0-2 days and the oldest 11-14 years. The samples were taken at the beginning of surgery. Results: Gestational age was a major determinant of the total muscle carnitine concentration in newborns (Spearman's rs= 0.692, P<0.01). This concentration was low during the first year, but subsequently did not differ between age groups. In neonates the median value (range) for total carnitine concentration in skeletal muscle was 5.9 (2.2-15.9) µmol/g dry weight and the free to total carnitine ratio was 62 (31-81)%. In children 1-12 months old the corresponding figures were 6.0 (3.5-7.9) µmol/g dry weight and 51 (28-71)% and in those 1-14 years they were 12.1 (6.6-17.4) µmol/g dry weight and 76 (42-92)%. Conclusion: This study shows that muscle carnitine concentrations in newborns are dependent on gestational age. The data suggest that there is an accretion of carnitine in skeletal muscle during the first year of life. Reference intervals are given.
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