Search results for "llop"

Supramolecular chemistry of metalloporphyrins

2009

International audience

Effect of different concentrations of specific inhibitor of matrix metalloproteinases on the shear bond strength of self-adhesive resin cements to de…

2017

Background Considering the probability of chemical and enzymatic reactions between matrix metalloproteinases (MMPs) in the dentin structure and their specific inhibitors, the aim of the present study was to evaluate the effect of different concentrations of specific inhibitor of MMPs (galardin) on the shear bond strength of self-adhesive resin cements to dentin. Material and Methods Forty-eight sound human premolars were mounted in self-cured acrylic resin after removal of the enamel on the buccal and lingual surfaces. The dentin surfaces achieved were polished and prepared with 600-grit silicon carbide paper. The samples were divided into 3 groups (n=16) based on the concentration of galar…

2021

Insights from sodium into the impacts of elevated pCO2 and temperature on bivalve shell formation

2017

Ocean acidification and warming are predicted to affect the ability of marine bivalves to build their shells, but little is known about the underlying mechanisms. Shell formation is an extremely complex process requiring a detailed understanding of biomineralization processes. Sodium incorporation into the shells would increase if bivalves rely on the exchange of Na+/H+ to maintain homeostasis for shell formation, thereby shedding new light on the acid-base and ionic regulation at the calcifying front. Here, we investigated the combined effects of seawater pH (8.1, 7.7 and 7.4) and temperature (16 and 22 °C) on the growth and sodium composition of the shells of the blue mussel, Mytilus edul…

Drivers of shell growth of the bivalve, Callista chione (L. 1758) - Combined it environmental and biological factors

2018

WOS:000426027100014; Seasonal shell growth patterns were analyzed using the stable oxygen and carbon isotope values of live-collected specimens of the bivalve Callista chione from two sites in the Adriatic Sea (Pag and Cetina, Croatia). Micromilling was performed on the shell surface of three shells per site and shell oxygen isotopes of the powder samples were measured. The timing and rate of seasonal shell growth was determined by aligning the delta O-18(shell)-derived temperatures so that the best fit was achieved with the instrumental temperature curve. According to the data, shells grew only at very low rates or not at all during the winter months, i.e., between January and March. Shell…

Arable-weed flora and its pollen representation: A case study from the eastern part of France

2007

International audience; Local pollen deposition in human-influenced vegetation types is studied with the aim of establishing the relationship between arable-weed vegetation and its pollen representation as an aid in interpreting human presence and impact on vegetation from pollen assemblages. The study area is located in the Franche-Comté region, eastern part of France. The presence of plants within 100 m2 plots and their pollen representation in moss samples within the same plots was recorded from different crops and annual fallows. Patterns in the vegetation and pollen assemblages were investigated separately using principal coordinate analysis (PCoA). Procrustean co-inertia analysis (PCI…

Understanding processes at the origin of species flocks with a focus on the marine Antarctic fauna

2017

Species flocks (SFs) fascinate evolutionary biologists who wonder whether such striking diversification can be driven by normal evolutionary processes. Multiple definitions of SFs have hindered the study of their origins. Previous studies identified a monophyletic taxon as a SF if it displays high speciosity in an area in which it is endemic (criterion 1), high ecological diversity among species (criterion 2), and if it dominates the habitat in terms of biomass (criterion 3); we used these criteria in our analyses. Our starting hypothesis is that normal evolutionary processes may provide a sufficient explanation for most SFs. We thus clearly separate each criterion and identify which biolog…

Experimental contact zones reveal causes and targets of sexual selection in hybridizing lizards

2016

Divergence in sexually selected traits in allopatry should affect the degree and direction of hybridization. However, few studies have established the causes and targets of sexual selection during secondary contact. Common wall lizards (Podarcis muralis) from north-central Italy have highly exaggerated male sexual traits compared to populations in Western Europe. Using experimental populations, we show that this creates asymmetries in male dominance, spatial habitat use and reproductive success upon secondary contact. Hybridization occurred almost exclusively between males of the Italian lineage and females of the Western European lineage. We provide evidence to suggest stronger ongoing sel…

Origin and distribution of desert ants across the Gibraltar Straits

2017

The creation of geographic barriers has long been suspected to contribute to the formation of new species. We investigated the phylogeography of desert ants in the western Mediterranean basin in order to elucidate their mode of diversification. These insects which have a low dispersal capacity are recently becoming important model systems in evolutionary studies. We conducted an extensive sampling of species belonging to the Cataglyphis albicans group in the Iberian Peninsula (IP) and the northern Morocco (North Africa; NA). We then combined genetic, chemical and morphological analyses. The results suggest the existence of at least three and five clades in the IP and NA, respectively, whose…

DNA Taxonomy Confirms the Identity of the Widely-Disjunct Mediterranean and Atlantic Populations of the Tufted Ghost Crab Ocypode cursor (Crustacea: …

2019

The distribution area of the tufted ghost crab Ocypode cursor includes two widely separate sub-areas, i.e. the tropical and subtropical Atlantic coasts of Africa and Macaronesia, and the central-eastern Mediterranean basin. The current disjunct distribution of the species is possibly the remnant of a previous wider and continuous distribution area that was fragmented during the Pleistocene, with the disappearance of the species from the temperate Atlantic Ocean and the western Mediterranean basin, and its survival in the warmer areas of the eastern Atlantic and the Mediterranean Sea. Such disjunction is thus compatible with an ancient isolation between the Mediterranean and Atlantic populat…