Search results for "Niza"
showing 10 items of 7898 documents
Impact of sewage sludges on Medicago truncatula symbiotic proteome
2004
The effects of sewage sludges were investigated on the symbiotic interactions between the model plant Medicago truncatula and the arbuscular mycorrhizal fungus Glomus mosseae or the rhizobial bacteria Sinorhizobium meliloti. By comparison to a control sludge showing positive effects on plant growth and root symbioses, sludges enriched with polycylic aromatic hydrocarbons or heavy metals were deleterious. Symbiosis-related proteins were detected and identified by two-dimensional electrophoresis and matrix-assisted laser desorption ionization mass spectrometry, and image analysis was used to study the effects of sewage sludges on M. truncatula symbiotic proteome.
Late Cretaceous-Early Eocene origin of yams (Dioscorea, Dioscoreaceae) in the Laurasian Palaearctic and their subsequent Oligocene-Miocene diversific…
2015
Aim: Dioscorea (Dioscoreaceae) is a predominantly pantropical genus (< 600 species) that includes the third most important tropical tuber crop and species of pharmacological value. Fossil records from both the Northern and Southern Hemispheres were used to test hypotheses about the origin of the genus Dioscorea, and to examine potential macroevolutionary processes that led to its current distribution. Location: Pantropical distribution. Methods: Divergence times were estimated using the most comprehensive phylogeny of the group published to date based on plastid sequences and fossil calibrations, applying a relaxed-clock model approach. Ancestral areas and range shifts were reconstructed us…
Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis
2013
International audience; The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but thi…
Diversity patterns and biogeography of Diaptomidae (Copepoda, Calanoida) in the Western Palearctic
2017
Diaptomid copepods are an important component of biodiversity in inland aquatic ecosystems worldwide but to date little is known about the historical and ecological factors that determined their current distribution. In the present paper, a critical review of the available literature on diaptomid species distribution in the Western Palearctic was performed, and a biogeographical analysis was carried out on the roles that spatial, current environmental, and historical (paleoclimatic) factors played on their actual distribution in this large area. The results show a clear pattern of colonization which is only partially overlapping what has been recently proposed for other terrestrial and aqua…
Blowing in the wind: how many roads can a phytoplanktont walk down? A synthesis on phytoplankton biogeography and spatial processes
2015
The selected theme of the 17th Workshop of the International Association for Phytoplankton Taxonomy and Ecology (IAP), ‘‘Biogeography and Spatial Patterns of Biodiversity of Freshwater Phytoplankton,’’ offered the opportunity to explore one neglected aspect of phytoplankton ecology: the distribution of species in the geographic space. This paper summarizes the outcomes of 20 selected contributions among those presented at the workshop. The articles report the results from studies carried out in five continents (only Oceania is not represented) and on a wide array of aquatic ecosystems (deep and shallow natural lakes, man-made lakes, temporary and permanent ponds, rivers). The topics analyze…
A Network Model for the Correlation between Epistasis and Genomic Complexity
2008
The study of genetic interactions (epistasis) is central to the understanding of genome organization and evolution. A general correlation between epistasis and genomic complexity has been recently shown, such that in simpler genomes epistasis is antagonistic on average (mutational effects tend to cancel each other out), whereas a transition towards synergistic epistasis occurs in more complex genomes (mutational effects strengthen each other). Here, we use a simple network model to identify basic features explaining this correlation. We show that, in small networks with multifunctional nodes, lack of redundancy, and absence of alternative pathways, epistasis is antagonistic on average. In c…
Social equity and marine protected areas: Perceptions of small-scale fishermen in the Mediterranean Sea
2020
Abstract Global conservation policy requires the scaling up of effectively and equitably managed networks of marine protected areas (MPAs). While progress has been made on spatial coverage, the fundamental aspects of effectiveness and equity are falling short. Past research has focused on management effectiveness in MPAs, but less attention has been given to social equity though it is an ethical imperative and instrumental to conservation. This study assessed the perceptions of SSF regarding recognitional, procedural and distributional dimensions of social equity using quantitative surveys in 11 MPAs across 6 countries on the Mediterranean Sea. To do so, we developed individual indicators f…
Behavioral syndrome in a native and an invasive hymenoptera species
2014
Recent studies have focused on the role of behavior in biological invasions. Individuals may differ consistently in time for several behavioral traits (personality) which covary(behavioralsyndrome)resultingindifferentbehavioraltypes,someofthemfavoring invasion. Social hymenopterans have a strong potential to be invaders and their success depends primarily on the foundresses' ability to found viable colonies. They are expected to be active, explorative and bold for optimally establishing their nest. In Europe, 2 hornet species coexist: the native Vespa crabro and the invasive Vespa velutina. These 2 species may compete for nesting sites and we suggest that the initial success of V. velutina …
Influence of leaf age on induced resistance in grapevine against Plasmopara viticola
2012
International audience; Sulfated laminarin (PS3) has previously been shown to induce resistance of grapevine leaves against the oomycete Plasmopara viticola, the causal agent of grape downy mildew. Here, we observed that the level of PS3-induced resistance (PS3-IR) was higher in the adult leaf (in position P3) than in the younger, not fully expanded leaf (in position P1, located above P3). By investigating grapevine defense reactions upon PS3 treatment and inoculation, we found that the production of H2O2, of phytoalexins, and the deposition of phenolics were more abundant in P3 than in P1 leaves. In addition, PS3 significantly reduced stomatal colonization by zoospores only in P3 leaves. T…
A new rationale for not picking low hanging fruits: The separation of ownership and control
2019
Recent attempts at explaining the energy-efficiency gap rely on considerations related to organizational and behavioral/cognitive failures. In this paper, we build on the strategic delegation literature to advance a complementary explanation. It is shown that strategic market interaction may encourage business owners to instill a bias against energy efficiency in managerial compensation contracts. Since managers respond to financial incentives, their decisions will reflect this bias, resulting in lack of investment.