Search results for "types"
showing 10 items of 956 documents
The Greenland shark Somniosus microcephalus—Hemoglobins and ligand-binding properties
2017
A large amount of data is currently available on the adaptive mechanisms of polar bony fish hemoglobins, but structural information on those of cartilaginous species is scarce. This study presents the first characterisation of the hemoglobin system of one of the longest-living vertebrate species (392 +/- 120 years), the Arctic shark Somniosus microcephalus. Three major hemoglobins are found in its red blood cells and are made of two copies of the same a globin combined with two copies of three very similar beta subunits. The three hemoglobins show very similar oxygenation and carbonylation properties, which are unaffected by urea, a very important compound in marine elasmobranch physiology.…
Essential features of the polytypic charoite-96 structure compared to charoite-90
2011
AbstractCharoite, ideally (K,Sr,Ba,Mn)15–16(Ca,Na)32[(Si70(O,OH)180)](OH,F)4·nH20, is a rock-forming mineral from the Murun massif in Yakutia, Sakha Republic, Siberia, Russia, where it occurs in a unique alkaline intrusion. Charoite occurs as four different polytypes, which are commonly intergrown in nanocrystallme fibres. We report the structure of charoite-96(a =32.11(6),b =19.77(4),c =7.23(1) Å, β = 95.85(9)°,V =4565(24) Å3, space groupP21/m),which was solvedab initioby direct methods on the basis of 2676 unique electron diffraction reflections collected by automated diffraction tomography and refined toR1/wR2=0.34/0.37. The structure of charoite-96 is related to that of the charoite-90,…
Spatial variability of the relationships of runoff and sediment yield with weather types throughout the Mediterranean basin
2019
Este artículo contiene 16 páginas, 6 figuras, 2 tablas.
New palaeoecological approaches to interpret climatic fluctuations in Holocene sites of the Pampean region of Argentina
2021
The apparently regular and favourable climate that characterizes the Holocene as an interglacial period shows, however, important climatic instability well documented in the Northern Hemisphere. These fluctuations from colder to warmer or wetter to drier affected both biodiversity and human societies in the last 12,000 years, although the impact in Southern America is still poorly known. We are here investigating the biodiversity of small mammal faunas, more sensitive to climatic changes than large mammals, combining taphonomic and palaeoecological data in the Argentine Pampas to better understand the global nature and effect of these Holocene climatic fluctuations. This paper is pioneering…
Accuracy of IKONOS for mapping benthic coral-reef habitats: a case study from the Puerto Morelos Reef National Park, Mexico
2012
International audience; Reefs are being threatened by global warming, natural disasters, and the increased pressure of the global population. These habitats are in urgent need of mapping at high resolution so that these threats can be quantified. Remote sensing can potentially provide such quantitative data. In this article, we attempt to map benthic coral-reef habitats at the Puerto Morelos Reef National Park in Yucatan Peninsula (Mexico) and to assess the accuracy of the technique in providing a baseline data for future monitoring of changes and evolution of the reef system. An IKONOS image was used in combination with checkpoint ground sampling and classified using a supervised maximum l…
Evaluation of chloroplast genome annotation tools and application to analysis of the evolution of coffee species.
2018
International audience; Chloroplast sequences are widely used for phylogenetic analysis due to their high degree of conservation in plants. Whole chloroplast genomes can now be readily obtained for plant species using new sequencing methods, giving invaluable data for plant evolution However new annotation methods are required for the efficient analysis of this data to deliver high quality phylogenetic analyses. In this study, the two main tools for chloroplast genome annotation were compared. More consistent detection and annotation of genes were produced with GeSeq when compared to the currently used Dogma. This suggests that the annotation of most of the previously annotated chloroplast …
Taxonomic and nomenclatural revision of Carlos Pau’s names in Hieracium (Asteraceae)
2019
During a study on the taxonomy of Hieracium for the Flora iberica project, several names turned out to be not yet typified. In the present paper, 63 names of Hieracium are treated. In order to fix their applications, nomenclatural types for 28 Pau’s names in the genus Hieracium are designated (27 lectotypes, 1 neotype and 1 epitype). All the type material available is listed with full label data, and some nomenclatural and taxonomic comments are provided.
Long-Distance Travellers: Phylogeography of a Generalist Parasite, Pholeter gastrophilus, from Cetaceans
2017
We studied the phylogeography and historical demography of the most generalist digenean from cetaceans, Pholeter gastrophilus, exploring the effects of isolation by distance, ecological barriers and hosts' dispersal ability on the population structure of this parasite. The ITS2 rDNA, and the mitochondrial COI and ND1 from 68 individual parasites were analysed. Worms were collected from seven oceanic and coastal cetacean species from the south western Atlantic (SWA), central eastern Atlantic, north eastern Atlantic (NEA), and Mediterranean Sea. Pholeter gastrophilus was considered a single lineage because reciprocal monophyly was not detected in the ML cladogram of all individuals, and seque…
High and uneven levels of 45S rDNA site-number variation across wild populations of a diploid plant genus (Anacyclus, Asteraceae)
2017
The nuclear genome harbours hundreds to several thousand copies of ribosomal DNA. Despite their essential role in cellular ribogenesis few studies have addressed intrapopulation, interpopulation and interspecific levels of rDNA variability in wild plants. Some studies have assessed the extent of rDNA variation at the sequence and copy-number level with large sampling in several species. However, comparable studies on rDNA site number variation in plants, assessed with extensive hierarchical sampling at several levels (individuals, populations, species) are lacking. In exploring the possible causes for ribosomal loci dynamism, we have used the diploid genus Anacyclus (Asteraceae) as a suitab…
The role of the Strait of Gibraltar in shaping the genetic structure of the Mediterranean Grenadier, Coryphaenoides mediterraneus, between the Atlant…
2017
24 pages, 4 figures, 4 tables, supplementary information https://dx.doi.org/10.1371/journal.pone.0174988.-- Data Availability: The mtDNA COI sequences can be accessed at BOLD systems through the sample ID: ME-9911; ME-11972; ME-13727; GLF011. New mtDNA COI sequences can be accessed at GenBank by the accession numbers KY345206 - KY345398. GenBank accession numbers for close related species of C. mediterraneus are: Coryphaenoides striaturus - KX656427.1, KX656428.1; Coryphaenoides murray - KX656411.1, KX656410.1; Coryphaenoides carapinus - KX656382.1, KX656381.1; Coryphaenoides brevibarbis - KX656377.1, KX656376.1, KX656375.1. An alignment in fasta with all the haplotypes and respective frequ…