| 11. |
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| 12. |
- Olsson, Mats, 1960, et al.
(författare)
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Haldane rules: costs of outbreeding at production of daughters in sand lizards
- 2004
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 7:10, s. 924-928
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Tidskriftsartikel (refereegranskat)abstract
- Haldane's rule is one of the most widely applicable paradigms in evolutionary biology, stating that in species crossings, the heterogametic sex will suffer more severely in terms of sterility and inviability. We address this in a within-species outbreeding situation by assessing the risk of producing inviable offspring depending on the sex ratio of the clutch produced in between-population crossings in the laboratory. In crossings between male and female sand lizards (Lacerta agilis) from two different sampling regions, one in Sweden, one in central Europe, risk of gametic incompatibility is unaffected by outbreeding, but offspring from between-population crossings show 300% higher malformation frequency and 10% lower hatching success. The risk of having inviable offspring increases with the production of daughters, i.e. the hemizygous sex in this species (ZW). Such sex-specific genetic costs of offspring production need to be incorporated into life history ecology, e.g. sex allocation theory.
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| 13. |
- Olsson, Mats, 1960, et al.
(författare)
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IN HOT PURSUIT: FLUCTUATING MATING SYSTEM AND SEXUAL SELECTION IN SAND LIZARDS
- 2011
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Ingår i: EVOLUTION. - : Wiley. - 0014-3820. ; Online 5 NOV 2010, s. 574-583
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: A changing climate is expected to have profound effects on many aspects of ectotherm biology. We report on a decade-long study of free-ranging sand lizards (Lacerta agilis), exposed to an increasing mean mating season temperature and with known operational sex ratios. We assessed year-to-year variation in sexual selection on body size and postcopulatory sperm competition and cryptic female choice. Higher temperature was not linked to strength of sexual selection on body mass, but operational sex ratio (more males) did increase the strength of sexual selection on body size. Elevated temperature increased mating rate and number of sires per clutch with positive effects on offspring fitness. In years when the "quality" of a female's partners was more variable (in standard errors of a male sexual ornament), clutches showed less multiple paternity. This agrees with prior laboratory trials in which females exercised stronger cryptic female choice when male quality varied more. An increased number of sires contributing to within-clutch paternity decreased the risk of having malformed offspring. Ultimately, such variation may contribute to highly dynamic and shifting selection mosaics in the wild, with potential implications for the evolutionary ecology of mating systems and population responses to rapidly changing
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| 14. |
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| 15. |
- Sparv, David, et al.
(författare)
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Assessment of increasing intravenous adenosine dose in fractional flow reserve
- 2017
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Ingår i: BMC Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261. ; 17:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Effects of increased adenosine dose in the assessment of fractional flow reserve (FFR) were studied in relation to FFR results, hemodynamic effects and patient discomfort. FFR require maximal hyperemia mediated by adenosine. Standard dose is 140 μg/kg/min administrated intravenously. Higher doses are commonly used in clinical practice, but an extensive comparison between standard intravenous dose and a high dose (220 μg/kg/min) has previously not been performed. Methods: Seventy-five patients undergoing FFR received standard dose adenosine, followed by high dose adenosine. FFR, mean arterial pressure (MAP) and heart rate (HR) were analyzed. Patient discomfort measured by Visual Analogue Scale (VAS) was assessed. Results: No significant difference was found between the doses in FFR value (0.85 [0.79-0.90] vs 0.85 [0.79-0.89], p = 0.24). The two doses correlated well irrespective of lesion severity (r = 0.86, slope = 0.89, p = <0.001). There were no differences in MAP or HR. Patient discomfort was more pronounced using high dose adenosine (8.0 [5.0-9.0]) versus standard dose (5.0 [2.0-7.0]), p = <0.001. Conclusions: Increased dose adenosine does not improve hyperemia and is associated with increased patient discomfort. Our findings do not support the use of high dose adenosine. Trial registration: Retrospective Trial registration: Current Controlled Trials ISRCTN14618196. Registered 15 December 2016.
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| 16. |
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