Search results for "Systematics"
showing 10 items of 6702 documents
Lectotypification of the spikemosses Selaginella denticulata and S. ornithopodioides (Selaginellaceae, Lycopsida)
2015
The typification of the names Selaginella denticulata (L.) Spring (≡ Lycopodium denticulatum L.) and S . ornithopodioides (L.) Spring (≡ L . ornithopodioides L.) (Selaginellaceae) is discussed. A specimen at LINN is designated as the lectotype of S . denticulata , and a specimen at BM is designated as the second-step lectotype of the name S . ornithopodioides .
Flawed Meta-Analysis of Biodiversity Effects of Forest Management
2010
It appears that the negative effect of forest managementon biodiversity has become an axiom. Whether the neg-ative effect, however, is a fact based on solid empiricalevidence is not self-evident. Most of the studies that ad-dress the issue suffer from a lack of geographic extentand taxonomic narrowness. Therefore, a synthesis draw-ing together results from the individual studies is direlyneeded. In their recent paper, Paillet et al. (2010) rise tothis challenge and present a formal pan-European meta-analysis of data from 49 papers representing 120 indi-vidual comparisons across 10 taxonomic groups. Theirsynthesis has the potential to be a landmark paper inecological research, but also to af…
Variation between Self- and Mutual Assessment in Animal Contests
2014
Limited resources lead animals into conflicts of interest, which are resolved when an individual withdraws from a direct contest. Current theory suggests that the decision to withdraw can be based on a threshold derived from an individual’s own state (self-assessment) or on a comparison between their own state and their opponent’s (mutual assessment). The observed variation between these assessment strategies in nature does not conform to theory. Thus, we require theoretical developments that explain the functional significance of different assessment strategies. We consider a hawk-dove game with two discrete classes that differ in fighting ability, in which the players strategically decide…
Review of the Chilean Anthicidae Sensu Lato (Insecta: Coleoptera), with Critical Notes on the Lemodinae and Tomoderinae, New Descriptions and Synonyms
2021
An account of the Anthicidae (ant-like flower beetles) and associated incertae sedis groups of Chile is presented. Forty seven species and subspecies are confirmed for the country (Anthicinae, Copobaeninae, Eurygeniinae, Lagrioidinae, Lemodinae, Tomoderinae), including 11 new to science: Ischyropalpus aberratus, I. quadrimaculatus, I. similis, Sapintus costae, Tomoderus cavithorax, T. differens, T. melanocephalus, T. nahuelbuta, Trichananca inexpectata, T. neotropica, T. poggiispp. nov.ProtoanthicusMoore et Vidal, 2005 is found to be congeneric with Trichananca Blackburn, 1891, a new synonym and three new combinations are proposed: Trichananca marziae (Moore et Vidal, 2005) comb. nov., T. p…
Lulwoana sp., a dark septate endophyte (DSE) in roots of Posidonia oceanica (L.) Delile seagrass
2014
Posidonia oceanica is the most common, widespread and important monocotyledon seagrass in the Mediterranean Basin, and hosts a large biodiversity of species, including microorganisms with key roles in the marine environment. In this study, we ascertain the presence of a fungal endophyte in the roots of P. oceanica growing on different substrata (rock, sand and matte) in two Sicilian marine meadows. Staining techniques on root fragments and sections, in combination with microscope observations, were used to visualise the fungal presence and determine the percentage of fungal colonisation (FC) in this tissue. In root fragments, statistical analysis of the FC showed a higher mean in roots anch…
Diagnosis of flavobacteriosis by direct amplification of rRNA genes
2002
A broad-range bacterial PCR method with universal 16S rDNA targeting primers and bacterial cultivation was used to identify the putative pathogen in flavobacterial outbreaks. Restriction fragment length polymorphism (PCR-RFLP) analysis and sequencing of the partial 16S rDNA PCR products of 10 skin samples and 10 representative isolates derived from the same fish specimens revealed differences between direct molecular and cultivation-based analysis. Flavobacterium columnare-like sequences dominated in the direct molecular analysis in most cases, whereas most of the isolates belonged to a phylogenetically heterogeneous group of flavobacteria clustering with F. hibernum. F. columnare was isola…
ABO genotyping by PCR-RFLP and cloning and sequencing
2005
A refined PCR-RFLP based method was established to genotype ABO blood groups. The main objective of this study was to make the techniques also suitable for working with degraded DNA. Specific primer design was carried out to choose fragments shorter than 200 bp as necessary in forensic and archaeological applications. Four fragments of exon 6 and 7 of the ABO gene were amplified and digested by in total 7 restriction endonucleases. Particular attention was paid to the base changes at nucleotide positions 261(delG), 297, 526, 703, 721, 771, 796 and 1060(delC) in order to distinguish the six common alleles A101, A201, B, O01, O02 and O03. Furthermore, this method also enables determination of…
Phylogenetic relationship of ubiquitin repeats in the polyubiquitin gene from the marine sponge Geodia cydonium
1994
Ubiquitin is a 76-residue protein which is highly conserved among eukaryotes. Sponge (Porifera) ubiquitin, isolated from Geodia cydonium, is encoded by a gene (termed GCUBI) with six repeats, GCUBI-1 to GCUBI-6. All repeat units encode the same protein (with one exception: GCUBI-4 encodes ubiquitin with a change of Leu to Val at position 71). On the nt level the sequences of the six repeats differ considerably. All changes (except in GCUBI-4) are silent substitutions, which do not affect the protein structure. However, there is one major difference between the repeats: Codons from both codon families (TCN and AGPy) are simultaneously used for the serine at position 65. Using this characteri…
Analysis of the Overdispersed Clock in the Short-Term Evolution of Hepatitis C Virus: Using the E1/E2 Gene Sequences to Infer Infection Dates in a Si…
2006
Abstract The assumption of a molecular clock for dating events from sequence information is often frustrated by the presence of heterogeneity among evolutionary rates due, among other factors, to positively selected sites. In this work, our goal is to explore methods to estimate infection dates from sequence analysis. One such method, based on site stripping for clock detection, was proposed to unravel the clocklike molecular evolution in sequences showing high variability of evolutionary rates and in the presence of positive selection. Other alternatives imply accommodating heterogeneity in evolutionary rates at various levels, without eliminating any information from the data. Here we pre…
Succession et remplacements de communautés à brachiopodes en régime de sédimentation discontinue (Jurassique Moyen, Bourgogne, France)
1993
Abstract Sequence stratigraphy throws a new and seminal light on the fossil record and helps in determining the respective role played by external control (community replacement) and internal control (paleoecological succession) in the temporal “train” of marine benthic paleocommunities. Five brachiopod-dominated communities (C1–C5) are recognized and their temporal “train” described, during the uppermost Bathonian-lower Callovian interval in Burgundy. The first series (C1–C3) exhibits a trend interpreted as a paleoecological succession and the next two (C3–C4, C4–C5) as community replacements. Within the scope of sequence stratigraphy, the paleoecological succession comes at the end of a t…