Search results for "Form."
showing 10 items of 43419 documents
New insights into the enameloid microstructure of batoid fishes (Chondrichthyes)
2016
Chondrichthyan teeth are capped with a hypermineralized tissue known as enameloid. Its microstructure displays a hierarchical organization that has increased in structural complexity from a homogenous single-crystallite enameloid (SCE) in early Chondricthyans to the complex multilayered enameloid found in modern sharks (consisting of bundles of crystallites arranged in intriguing patterns). Recent analyses of the enameloid microstructure in batoid fishes, focused on Myliobatiformes and fossil taxa, point to the presence of a bundled (or fibred) multilayered enameloid, a condition proposed as plesiomorphic for Batoidea. In this work, we provide further enameloid analysis for a selection of t…
Forecasting the volatility of biofuel feedstock prices: the US evidence
2019
Given that, nowadays, 40% of the US corn crop is used for biofuel production, there is a growing concern that the rise in biofuel production might lead to an increase in food prices. However, it is also obvious that significant growth in biofuel use has minimized the demand for fossil fuel and has hence reduced the volume of carbon emissions. It is therefore crucial to model corn market volatility precisely because such an estimate could play a vital role in stabilizing food and biofuel market prices. For this purpose, we consider using the information content of the corn implied volatility (CIV) index to predict the corn futures market return volatility. Using symmetric and asymmetric GARC…
A minimalist macroparasite diversity in the round goby of the Upper Rhine reduced to an exotic acanthocephalan lineage.
2018
AbstractThe round goby, Neogobius melanostomus, is a Ponto-Caspian fish considered as an invasive species in a wide range of aquatic ecosystems. To understand the role that parasites may play in its successful invasion across Western Europe, we investigated the parasitic diversity of the round goby along its invasion corridor, from the Danube to the Upper Rhine rivers, using data from literature and a molecular barcoding approach, respectively. Among 1666 parasites extracted from 179 gobies of the Upper Rhine, all of the 248 parasites barcoded on the c oxidase subunit I gene were identified as Pomphorhynchus laevis. This lack of macroparasite diversity was interpreted as a loss of parasites…
Moving in the Anthropocene: Global reductions in terrestrial mammalian movements
2018
Made available in DSpace on 2018-11-26T17:44:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-26 Robert Bosch Foundation Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-…
Abundance–variance and abundance–occupancy relationships in a marine host–parasite system: The importance of taxonomy and ecology of transmission
2011
Abundance-occupancy and abundance-variance relationships are two of the most general macroecological patterns capturing essential fundamentals of the structuring of species distributions and are widely documented for free-living animal and plant species populations at different spatial scales. However, empirical data for parasites have been gathered using appropriate sampling designs only recently. We performed analyses across species of the variation in infection parameters and patterns of aggregation of the most widespread parasites in the marine sparid fish Boops boops across seven localities of two marine biogeographical regions, the North East Atlantic and the Mediterranean. We used a …
NO contributes to cadmium toxicity in Arabidopsis thaliana by mediating an iron deprivation response
2009
Nitric oxide (NO) functions as a cell-signaling molecule in plants. In particular, a role for NO in the regulation of iron homeostasis and in the plant response to toxic metals has been proposed. Here, we investigated the synthesis and the role of NO in plants exposed to cadmium (Cd(2+)), a nonessential and toxic metal. We demonstrate that Cd(2+) induces NO synthesis in roots and leaves of Arabidopsis (Arabidopsis thaliana) seedlings. This production, which is sensitive to NO synthase inhibitors, does not involve nitrate reductase and AtNOA1 but requires IRT1, encoding a major plasma membrane transporter for iron but also Cd(2+). By analyzing the incidence of NO scavenging or inhibition of …
The DNA barcoding of Mediterranean combtooth blennies suggests the paraphyly of some taxa (Perciformes, Blenniidae)
2019
A dataset including novel and publicly available mtDNA COI sequences of 14 Mediterranean combtooth blenny species belonging to nine genera was assembled in order to provide a reference dataset for DNA barcoding studies. Some inconsistencies in the current taxonomy of some genera were observed. In particular, the monophyly of the genera Parablennius and Salaria is not supported by the present dataset and the absence of reciprocal monophyly between the morphospecies Salaria basilisca and S. pavo questions their status and stresses the need of a revision of the genus Salaria.
First evidence of underwater sounds emitted by the living fossils Lepidurus lubbocki and Triops cancriformis (Branchiopoda: Notostraca)
2021
Sound is the most effective means of communication in marine and freshwater ecosystems. However, no data about acoustic emissions from non-malacostracan crustaceans are currently available, so their ability to produce sounds is unknown. For the first time, this study investigated the sound produced by 2 tadpole shrimp species,Triops cancriformisandLepidurus lubbocki.L. lubbockiindividuals were collected from a natural temporary pond in Sicily (Italy), whereasT. cancriformisindividuals were obtained from eggs contained in sediment from a rock pool in Sardinia (Italy). In the laboratory, experimental tanks with the animals (one species at a time) were acoustically monitored. Both species prod…
Integrated membrane bioreactors modelling: A review on new comprehensive modelling framework
2021
International audience; Integrated Membrane Bioreactor (MBR) models, combination of biological and physical models, have been representing powerful tools for the accomplishment of high environmental sustainability. This paper, produced by the International Water Association (IWA) Task Group on Membrane Modelling and Control, reviews the state-of-the-art, identifying gaps for future researches, and proposes a new integrated MBR modelling framework. In particular, the framework aims to guide researchers and managers in pursuing good performances of MBRs in terms of effluent quality, operating costs (such as membrane fouling, energy consumption due to aeration) and mitigation of greenhouse gas…
Bayesian spatio-temporal discard model in a demersal trawl fishery
2014
Spatial management of discards has recently been proposed as a useful tool for the protection of juveniles, by reducing discard rates and can be used as a buffer against management errors and recruitment failure. In this study Bayesian hierarchical spatial models have been used to analyze about 440 trawl fishing operations of two different metiers, sampled between 2009 and 2012, in order to improve our understanding of factors that influence the quantity of discards and to identify their spatio-temporal distribution in the study area. Our analysis showed that the relative importance of each variable was different for each metier, with a few similarities. In particular, the random vessel eff…