Search results for "CAS"
showing 10 items of 26112 documents
Change in dominance determines herbivore effects on plant biodiversity
2018
Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis—that herbivore-induced changes in the competitive environment determine the response …
The cranium of Proviverra typica (Mammalia, Hyaenodonta) and its impact on hyaenodont phylogeny and endocranial evolution.
2019
19 pages; International audience; We describe the first endocast reconstruction of a hyaenodont mammal based on X‐ray microtomography. The endocast belongs to the type material of the European hyaenodont Proviverra typica. We performed phylogenetic analysis to contextualize the evolution of endocranial size and complexity in Hyaenodonta. We added several European hyaenodonts and modified several codings of the most recent character–taxon matrix established to question the relationships within Hyaenodonta. Including these new species in a phylogenetic analysis reveals a new clade: Hyaenodontoidea. Comparisons with several previously described endocasts show that there was an increase in comp…
Cuticular hydrocarbon profiles differ between ant body parts: implications for communication and our understanding of CHC diffusion.
2020
Abstract Insect cuticular hydrocarbons (CHCs) serve as communication signals and protect against desiccation. They form complex blends of up to 150 different compounds. Due to differences in molecular packing, CHC classes differ in melting point. Communication is especially important in social insects like ants, which use CHCs to communicate within the colony and to recognize nestmates. Nestmate recognition models often assume a homogenous colony odor, where CHCs are collected, mixed, and redistributed in the postpharyngeal gland (PPG). Via diffusion, recognition cues should evenly spread over the body surface. Hence, CHC composition should be similar across body parts and in the PPG. To te…
Hierarchy is Detrimental for Human Cooperation
2015
Studies of animal behavior consistently demonstrate that the social environment impacts cooperation, yet the effect of social dynamics has been largely excluded from studies of human cooperation. Here, we introduce a novel approach inspired by nonhuman primate research to address how social hierarchies impact human cooperation. Participants competed to earn hierarchy positions and then could cooperate with another individual in the hierarchy by investing in a common effort. Cooperation was achieved if the combined investments exceeded a threshold, and the higher ranked individual distributed the spoils unless control was contested by the partner. Compared to a condition lacking hierarchy, c…
Recombinant laccase from Pediococcus acidilactici CECT 5930 with ability to degrade tyramine
2017
Biogenic amines degradation by bacterial laccases is little known, so we have cloned and heterologously expressed, in E. coli, a new laccase from Pediococcus acidilactici CECT 5930 (Lpa5930), a lactic acid bacterium commonly found in foods able to degrade tyramine. The recombinant enzyme has been characterized by physical and biochemical assays. Here we report the optimization of expression and purification procedures of this laccase. DNA encoding sequence of laccase from P. acidilactici was amplified by PCR and cloned into the expression plasmid pET28a for induction by isopropyl-β-D-thiogalactoipyranoside. Protein expression was performed in E. coli BL21(DE3) harboring pGro7 plasmid expres…
Host dispersal shapes the population structure of a tick-borne bacterial pathogen
2020
Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevale…
An integrative identification guide to the Hydrozoa (Cnidaria) of Bocas del Toro, Panama
2018
This work is the first attempt to assess the biodiversity of the Hydrozoa in the Archipiélago de Bocas del Toro (Panamá, Caribbean Sea) using morphology and molecular taxonomy, and to produce field identification tools to help future identification and monitoring efforts in the area. We sampled, identified, vouchered, and barcoded 112 specimens of Hydrozoa from shallow coastal waters (0–22 m depth) in the Archipiélago de Bocas del Toro. The specimens belong to 70 taxa, of which 53 were identified at the species level, and 17 were identified at the genus or family level. We produced 64 sequences of the large ribosomal subunit of the mitochondrial RNA (mt lsu-rRNA, 16S), the genetic marker ge…
Reproductive inequalities in the acanthocephalan Corynosoma cetaceum: looking beyond 'crowding' effects.
2018
Background: At present, much research effort has been devoted to investigate overall (average) responses of parasite populations to specific factors, e.g., density-dependence in fecundity or mortality. However, studies on parasite populations usually pay little attention to individual variation (inequality) in reproductive success. A previous study on the acanthocephalan Corynosoma cetaceum in franciscana dolphins, Pontoporia blainvillei, revealed no overall intensity-dependent, or microhabitat effects, on mass and fecundity of worms. In this study, we investigated whether the same factors could influence mass inequalities for this species of acanthocephalan.Methods: A total of 10,138 speci…
Temporal variations in symbiotic hindgut protist community of the subterranean termite Reticulitermes lucifugus Rossi in Sicily.
2015
The dynamics of symbiotic protist communities of Reticulitermes lucifugus ‘‘Sicily’’ were investigated to assess the effects of seasonal environmental conditions and the termite’s feeding activity. In worker and soldier castes, the total protist population (total abundance), individual species abundances, and species proportions in their hindguts were examined monthly from December 2012 to February 2014. The main protist species taken into account were Dinenympha fimbriata Kirby, D. gracilis Leidy, Pyrsonympha flagellata Gras., Spirotrichonympha flagellata Grassi u. Fo` a, Holomastigotes elongatum Grassi u. Fo`a, and Trichonympha agilis Leidy, while others were not specifically identified, …
Identification of Stress Associated microRNAs in Solanum lycopersicum by High-Throughput Sequencing
2019
Tomato (Solanum lycopersicum) is one of the most important crops around the world and also a model plant to study response to stress. High-throughput sequencing was used to analyse the microRNA (miRNA) profile of tomato plants undergoing five biotic and abiotic stress conditions (drought, heat, P. syringae infection, B. cinerea infection, and herbivore insect attack with Leptinotarsa decemlineata larvae) and one chemical treatment with a plant defence inducer, hexanoic acid. We identified 104 conserved miRNAs belonging to 37 families and we predicted 61 novel tomato miRNAs. Among those 165 miRNAs, 41 were stress-responsive. Reverse transcription quantitative PCR (RT-qPCR) was used to valida…