Search results for "keys"

Neotropical primate evolution and phylogenetic reconstruction using chromosomal data

2017

Platyrrhini are a group of Neotropical primates living in central and south America, and have been extensively studied through morphological and molecular data in order to shed light on their phylogeny and evolution. Agreement on the main clades of Neotropical primates has been reached using different approaches, but many phylogenetic nodes remain under discussion. Contrasting hypotheses have been proposed, presumably due to different markers and the presence of polymorphisms in the features considered; furthermore, neither Neotropical primate biodiversity nor their taxonomy are entirely known. In our perspective, a cytogenetic approach can help by making an important contribution to the ev…

Additive effects of temperature and infection with an acanthocephalan parasite on the shredding activity of Gammarus fossarum (Crustacea: Amphipoda):…

2017

10 pages; International audience; Climate change can have critical impacts on the ecological role of keystone species, leading to subsequent alterations within ecosystems. The consequences of climate change may be best predicted by understanding its interaction with the cumulative effects of other stressors, although this approach is rarely adopted. However, whether this interaction is additive or interactive can hardly be predicted from studies examining a single factor at a time. In particular, biotic interactions are known to induce modifications in the functional role of many species. Here, we explored the effect of temperature on leaf consumption by a keystone freshwater shredder, the …

Landscape structure influences browsing on a keystone tree species in conservation areas

2020

Aspen is a keystone species in boreal forests. The future of aspen in many conservation areas is threatened by ungulate browsing. Our aim was to study the effect of browsing on aspen regeneration and population structure in conservation areas in Central Finland, and the effect of surrounding landscape structure on browsing. Aspen density varied greatly among and within conservation areas. In about half of the conservation areas, middle-sized aspens were scarce or missing, which indicates heavy browsing in the recent past. In addition, the number of dead, large aspens in advanced decay stages were rare. Browsing pressure varied greatly among the areas, but on average, a bit more than half of…

Climate Warming as a Possible Trigger of Keystone Mussel Population Decline in Oligotrophic Rivers at the Continental Scale

2018

AbstractThe effects of climate change on oligotrophic rivers and their communities are almost unknown, albeit these ecosystems are the primary habitat of the critically endangered freshwater pearl mussel and its host fishes, salmonids. The distribution and abundance of pearl mussels have drastically decreased throughout Europe over the last century, particularly within the southern part of the range, but causes of this wide-scale extinction process are unclear. Here we estimate the effects of climate change on pearl mussels based on historical and recent samples from 50 rivers and 6 countries across Europe. We found that the shell convexity may be considered an indicator of the thermal effe…

2021

Despite the wide recognition that strongly interacting species can influence distributions of other species, species interactions are often disregarded when assessing or projecting biodiversity distributions. In particular, it remains largely uncharted the extent to which the disappearance of a keystone species cast repercussions in the species composition of future communities. We tested whether an avian top predator can exert both positive and negative effects on spatial distribution of other species, and if these effects persist even after the predator disappeared. We acquired bird count data at different distances from occupied and non-occupied nests of Northern goshawks Accipiter genti…

Warmer temperatures reduce the influence of an important keystone predator

2017

Predator–prey interactions may be strongly influenced by temperature variations in marine ecosystems. Consequently, climate change may alter the importance of predators with repercussions for ecosystem functioning and structure. In North-eastern Pacific kelp forests, the starfish Pycnopodia helianthoides is known to be an important predator of the purple sea urchin Strongylocentrotus purpuratus. Here we investigated the influence of water temperature on this predator–prey interaction by: (i) assessing the spatial distribution and temporal dynamics of both species across a temperature gradient in the northern Channel Islands, California, and (ii) investigating how the feeding rate of P. heli…

Mixed company : a framework for understanding the composition and organization of mixed‐species animal groups

2020

Mixed‐species animal groups (MSGs) are widely acknowledged to increase predator avoidance and foraging efficiency, among other benefits, and thereby increase participants' fitness. Diversity in MSG composition ranges from two to 70 species of very similar or completely different phenotypes. Yet consistency in organization is also observable in that one or a few species usually have disproportionate importance for MSG formation and/or maintenance. We propose a two‐dimensional framework for understanding this diversity and consistency, concentrating on the types of interactions possible between two individuals, usually of different species. One axis represents the similarity of benefit types …

Pharmacokinetics and Pharmacodynamics of a 13-mer LNA-inhibitor-miR-221 in Mice and Non-human Primates

2016

Locked nucleic acid (LNA) oligonucleotides have been successfully used to efficiently inhibit endogenous small noncoding RNAs in vitro and in vivo. We previously demonstrated that the direct miR-221 inhibition by the novel 13-mer LNA-i-miR-221 induces significant antimyeloma activity and upregulates canonical miR-221 targets in vitro and in vivo. To evaluate the LNA-i-miR-221 pharmacokinetics and pharmacodynamics, novel assays for oligonucleotides quantification in NOD.SCID mice and Cynomolgus monkeys (Macaca fascicularis) plasma, urine and tissues were developed. To this aim, a liquid chromatography/mass spectrometry method, after solid-phase extraction, was used for the detection of LNA-i…

Chromosomal distribution of interstitial telomeric sequences in nine neotropical primates (Platyrrhini): possible implications in evolution and phylo…

2016

To localize interstitial telomeric sequences (ITSs) and to test whether their pattern of distribution could be linked to chromosomal evolution, we hybridized telomeric sequence probes (peptide nucleic acid, PNA) on metaphases of New World monkeys: Callithrix argentata, Callithrix jacchus, Cebuella pygmaea, Saguinus oedipus, Saimiri sciureus, Aotus lemurinus griseimembra, Aotus nancymaae (Cebidae), Lagothrix lagotricha (Atelidae) and Callicebus moloch (Pithecidae), characterized by a rapid radiation and a high rate of chromosomal rearrangements. Our analysis of the probe signal localization allowed us to show in all the species analysed, as normally, the telomeric location at the terminal en…

Eye-tracking revision processes of translation students and professional translators

2019

Great effort has been made to define and to measure revision competence in translation. However, combined eye tracking and keylogging have hardly been applied in revision research. We believe it is...