Search results for "ePRO"
showing 10 items of 6140 documents
Introduction of Mysis relicta (Mysida) reduces niche segregation between deep-water Arctic charr morphs
2019
This is a post-peer-review, pre-copyedit version of an article published in Hydrobiologia. The final authenticated version is available online at https://doi.org/10.1007/s10750-019-3953-4. Niche diversification of polymorphic Arctic charr can be altered by multiple anthropogenic stressors. The opossum-shrimp (Mysis relicta) was introduced to compensate for reduced food resources for fish following hydropower operations in Lake Limingen, central Norway. Based on habitat use, stomach contents, stable isotopes (δ13C, δ15N) and trophically transmitted parasites, the zooplanktivorous upper water-column dwelling ‘normal’ morph was clearly trophically separated from two sympatric deep-water morphs…
Social organization and the evolution of life-history traits in two queen morphs of the ant Temnothorax rugatulus.
2020
ABSTRACT During the evolution of social insects, not only did life-history traits diverge, with queens becoming highly fecund and long lived compared with their sterile workers, but also individual traits lost their importance compared with colony-level traits. In solitary animals, fecundity is largely influenced by female size, whereas in eusocial insects, colony size and queen number can affect the egg-laying rate. Here, we focused on the ant Temnothorax rugatulus, which exhibits two queen morphs varying in size and reproductive strategy, correlating with their colony's social organization. We experimentally tested the influence of social structure, colony and body size on queen fecundity…
Effects of different irrigation regimes on a super-high-density olive grove cv. “Arbequina”: vegetative growth, productivity and polyphenol content o…
2016
The effects of multiple irrigation regimes on the relationships among tree water status, vegetative growth and productivity within a super-high-density (SHD) “Arbequina” olive grove (1950 tree/ha) were studied for three seasons (2008–2010). Five different irrigation levels calculated as percentage of crop irrigation requirement using FAO procedures (Allen et al. in Crop evapotranspiration. Guidelines for computing crop water requirements. Irrigation and drainage paper 56. FAO, Rome, 1998) were imposed during the growing season. Periodically during the growing season, daytime stem water potential (Ψ STEM), inflorescences per branch, fruits per inflorescence and shoot absolute growth rate wer…
Reproductive and bloom patterns of Pelagia noctiluca in the Strait of Messina, Italy
2018
Special issue Vectors of change in the marine environment.-- 11 pages, 7 figures, 1 table, supplementary data https://doi.org/10.1016/j.ecss.2016.01.002
Extended haplodiploidy hypothesis
2019
P.R., M.P., and H.H. were supported by Academy of Finland (grant 258385 to M.P., grant 135970 to H.H., and 252411 to the Centre of Excellence in Biological Interactions), P.R. also by the Royal Society Newton International Fellowship, and H.H. also by the Kone Foundation. Evolution of altruistic behavior was a hurdle for the logic of Darwinian evolution. Soon after Hamilton formalized the concept of inclusive fitness, which explains how altruism can evolve, he suggested that the high sororal relatedness brought by haplodiploidy could be why Hymenopterans have a high prevalence in eusocial species, and why helpers in Hymenoptera are always female. Later it was noted that in order to capitali…
A possible link between parasite defence and residual reproduction
2007
Life-history theory centres around trade-offs between current and future reproduction, but we have little understanding of how such trade-offs are mediated. We supplementary fed Ural owls (Strix uralensis) during the nestling period and quantified parents' current and future life-history components as well as their physiological health by monitoring haematocrit, leucocyte profile, intra- and extracellular blood parasites. Feeding led to reduced parental effort but did not improve offspring viability, male parasite defence, or parental survival. Intracellular leucocytozoan infection was reduced in fed females which lasted to the following year's reproductive season (carry-over effect), when …
Light availability affects sex lability in a gynodioecious plant.
2016
PREMISE OF THE STUDY: Sex lability (i.e., gender diphasy) in plants is classically linked to the larger resource needs associated with the female sexual function (i.e., seed production) compared to the male function (i.e., pollen production). Sex lability in response to the environment is extensively documented in dioecious species, but has been largely overlooked in gynodioecious plants. METHODS: Here, we tested whether environmental conditions induce sex lability in the gynodioecious Geranium sylvaticum. We conducted a transplantation experiment in the field where plants with different sex expression were reciprocally transplanted between high light and low light habitats. We measured pla…
Retroconversion of docosapentaenoic acid (n-6): an alternative pathway for biosynthesis of arachidonic acid in Daphnia magna.
2013
The aim of this study was to assess metabolic pathways for arachidonic acid (20:4n-6) biosynthesis in Daphnia magna. Neonates of D. magna were maintained on [13C] enriched Scenedesmus obliquus and supplemented with liposomes that contained separate treatments of unlabeled docosapentaenoic acid (22:5n-6), 20:4n-6, linoleic acid (18:2n-6) or oleic acid (18:1n-9). Daphnia in the control treatment, without any supplementary fatty acids (FA) containing only trace amounts of 20:4n-6 (~0.3 % of all FA). As expected, the highest proportion of 20:4n-6 (~6.3 %) was detected in Daphnia that received liposomes supplemented with this FA. Higher availability of 18:2n-6 in the diet increased the proportio…
Male health status, signalled by courtship display, reveals ejaculate quality and hatching success in a lekking species.
2010
8 pages; International audience; Summary 1. The information content of secondary sexual traits and the benefits gathered by choosy females are at the heart of sexual selection theory. Indicator models of sexual selection assume that secondary sexual traits reflect the phenotypic/genetic quality of their bearers and that females gather benefits from choosing these high-quality males. 2. Here, we tested the idea that courtship display reflects the health status in a bird species with a lek-based mating system, the houbara bustard (Chlamydotis undulata undulata). A group of males was treated with the lipopolysaccharide (LPS) of the cell wall of the bacterium Escherichia coli during the seasona…
Island selection on mammalian life-histories: genetic differentiation in offspring size
2008
Abstract Background Since Darwin's pioneering work, evolutionary changes in isolated island populations of vertebrates have continued to provide the strongest evidence for the theory of natural selection. Besides macro-evolutionary changes, micro-evolutionary changes and the relative importance of natural selection vs. genetic drift are under intense investigation. Our study focuses on the genetic differentiation in morphological and life-history traits in insular populations of a small mammal the bank vole Myodes glareolus. Results Our results do not support the earlier findings for larger adult size or lower reproductive effort in insular populations of small mammals. However, the individ…