Search results for "Clad"
showing 10 items of 495 documents
Sinophysis and Pseudophalacroma are Distantly Related to Typical Dinophysoid Dinoflagellates (Dinophysales, Dinophyceae)
2011
Dinophysoid dinoflagellates are usually considered a large monophyletic group. Large subunit and small subunit (SSU) rDNA phylogenies suggest a basal position for Amphisoleniaceae (Amphisolenia,Triposolenia) with respect to two sister groups, one containing most Phalacroma species plus Oxyphysis and the other Dinophysis,Ornithocercus, Dinophysoid dinoflagellates are usually considered a large monophyletic group. Large subunit and small subunit (SSU) rDNA phylogenies suggest a basal position for Amphisoleniaceae (Amphisolenia,Triposolenia) with respect to two sister groups, one containing most Phalacroma species plus Oxyphysis and the other Dinophysis,Ornithocercus, Histioneis,Citharistes an…
Atrazine uptake, elimination, and bioconcentration by periphyton communities and Daphnia magna: effects of dissolved organic carbon.
2001
The bioconcentration and toxicokinetics of atrazine in three different periphyton communities and in laboratory reared Daphnia magna were studied in natural and artificial waters with different dissolved organic carbon (DOC) concentrations and qualities. The exposure concentrations were similar to those short-lived peak concentrations found in contaminated waters. Atrazine uptake and elimination were very fast, and the bioconcentration was low both in periphyton and D. magna. The bioconcentration factors in D. magna were approx. 16% of those in periphyton. The uptake and elimination rates were also higher in periphyton than in Daphnia. The periphyton properties affected the bioconcentration…
Characteristics of cellulose fibers from Opuntia ficus indica cladodes and its use as reinforcement for PET based composites
2021
With the aim of valorizing the unexplored Moroccan resources, Opuntia ficus indica (OFI) cladodes were proposed as a renewable source for the production of cellulose. In this work, cellulose microf...
Spoilage of oat bran by sporogenic microorganisms revived from soil buried 4000 years ago in Iranian archaeological site
2015
Abstract The Bronze Age archaeological site of Shahr-i Sokhta (30° 39′ N; 61° 24’ E), located today in southeastern Iran, Sistan region, is a special archaeological deposit in which the exceptional preservation of human, plant and animal remains, due to the dry climate of the region, can provide detailed information on one of the first complex proto-urban societies. In recent years, there has been growing interest in changes in local climate and environment as major reasons why the settlement was abandoned about 4000 years ago. Food shortage has been regarded as a direct effect of these changes. No attention has been paid to the potential health hazards associated with ancient urban/domesti…
The comparison of beta-thymosin homologues among metazoa supports an arthropod-nematode clade.
2000
The definition of an Ecdysozoa clade among the protostomians, including all phyla with a regularly molted alpha-chitin-rich cuticle, has been one of the most provocative hypotheses to arise from recent investigations on animal phylogeny. Here we present evidence in favor of an arthropod-nematode clade, from the comparison of beta-thymosin homologues among the Metazoa. Arthropods and nematodes share the absence of the highly conserved beta-thymosin form found in all other documented bilaterian phyla as well as sponges, and the possession of a very unusual, internally triplicated homologue of the beta-thymosin protein, unknown in other phyla. We argue that such discrete molecular character is…
Molecular phylogeny, biogeographic history, and evolution of cave-dwelling taxa in the European harvestman genusIschyropsalis(Opiliones: Dyspnoi)
2015
Abstract We estimated a multigenic molecular phylogeny and reconstructed biogeographic history for the European harvestman genus Ischyropsalis C.L. Koch 1839 (Dyspnoi). To reconstruct historical biogeographic patterns we conducted an algorithmic VIP analysis which revealed patterns consistent with a vicariance-dominated history. The existing morphology-based systematic framework for Ischyropsalis is mostly inconsistent with molecular phylogenetic results, and a new informal system is established that recognizes three main clades and several sub-clades. Species-level analyses revealed two non-monophyletic species (I. pyrenaea Simon 1872 and I. luteipes Simon 1872); subspecies of I. pyrenaea …
Toward a Phylogenetic Classification of the Lauraceae: Evidence from matK Sequences
2000
Abstract The larger part of the matK gene and the (3′−) adjacent spacer have been sequenced and used for phylogenetic analyses in 48 species of Lauraceae from all parts of their geographical range, and in three outgroup taxa. Except for the aberrant genera Hypodaphnis and Cassytha, the genetic divergence within the family is surprisingly low. In spite of this, several clades receive sufficient support to change our current concepts of relationships within the family. Particularly well supported is a Beilschmiedia–Cryptocarya clade that had been recognized by wood anatomy, but not in most of the recent morphological systems. The separation between taxa with involucrate and non-involucrate in…
The Phylogenetic Analysis of Variable-Length Sequence Data: Elongation Factor–1α Introns in European Populations of the Parasitoid Wasp Genus Pauesia…
2001
Elongation factor-1alpha (EF-1alpha) is a highly conserved nuclear coding gene that can be used to investigate recent divergences due to the presence of rapidly evolving introns. However, a universal feature of intron sequences is that even closely related species exhibit insertion and deletion events, which cause variation in the lengths of the sequences. Indels are frequently rich in evolutionary information, but most investigators ignore sites that fall within these variable regions, largely because the analytical tools and theory are not well developed. We examined this problem in the taxonomically problematic parasitoid wasp genus Pauesia (Hymenoptera: Braconidae: Aphidiinae) using con…
Phylogeny of prickly poppies,Argemone (Papaveraceae), and the evolution of morphological and alkaloid characters based on ITS nrDNA sequence variation
1999
Evolutionary relationships withinArgemone (Papaveraceae) were inferred from nucleotide variation in nuclear ribosomal DNA. A complete representation of the genus was achieved by using herbarium material to a large extent (74%). Four distinct clades can be recognized based on the molecular results. The support for the different clades varies greatly due to a very uneven distribution of characters. Although some clades are largely unresolved, some unexpected relationships, for example the sister group relationship of the relict speciesA. subintegrifolia to the rest ofArgemone, were found. The evolution of morphological and alkaloid characters against the background of the obtained phylogeny i…
Molecular phylogeny of Iberian Fordini (Aphididae: Eriosomatinae): implications for the taxonomy of generaFordaandParacletus
2009
Mediterranean representatives of the galling aphid tribe Fordini (Hemiptera: Aphididae: Eriosomatinae) are usually grouped under the subtribe term Fordina. Aphids within Fordina display two-year life cycles, alternating between Pistacia shrubs, where they induce conspicuous galls, and roots of Poaceae species. The high number of morphs present in a given species, the lack of knowledge of the complete cycle in some species, and the similarity between homologous morphs observed in different species pose many taxonomic problems in this group. We present results of a survey to elucidate the phylogenetic relationships among Fordini species present in the Iberian Peninsula and the Canary Islands.…