Search results for "Systematic"
showing 10 items of 7608 documents
Natural selection constrains personality and brain gene expression differences in Atlantic salmon (Salmo salar).
2015
ABSTRACT In stream-spawning salmonid fishes there is a considerable variation in the timing of when fry leave the spawning nests and establish a feeding territory. The timing of emergence from spawning nests appears to be related to behavioural and physiological traits, e.g. early emerging fish are bolder and more aggressive. In the present study, emerging Atlantic salmon (Salmo salar L.) alevins were sorted into three fractions: early, intermediate and late emerging. At the parr stage, behaviour, stress responses, hindbrain monoaminergic activity and forebrain gene expression were explored in fish from the early and late emerging fractions (first and last 25%). The results show that when s…
Phylogenetic analysis of the isopenicillin-N-synthetase horizontal gene transfer.
1996
A phylogenetic study of the isopenicillin-N-synthetase (IPNS) gene sequence from prokaryotic and lower eukaryotic producers of beta-lactam antibiotics by means of a maximum-likelihood approach has been carried out. After performing an extensive search, rather than invoking a global molecular clock, the results obtained are best explained by a model with three rates of evolution. Grouped in decreasing order, these correspond to A. nidulans and then to the rest of the eukaryotes and prokaryotes, respectively. The estimated branching date between prokaryotic and fungal IPNS sequences (852 +/- 106 MY) strongly supports the hypothesis that the IPNS gene was horizontally transferred from bacteria…
Insect Immune Evasion by Dauer and Nondauer Entomopathogenic Nematodes
2021
The immune response of animals, including insects, is overcome by some parasites. For example, dauer larvae (DL) of the obligate entomopathogenic nematodes (EPNs) Heterorhabditis and Steinernema can invade insects, evade their defenses, and cause death. Although DL were long assumed to be the only infective stage of nematodes, recent reports suggest that L2-L3 larvae of facultative EPNs are also capable of killing insects. There are no studies, to our knowledge, about the role of nonimmunological barriers (the exoskeleton and its openings) in avoiding infection by DL and L2-L3 larvae, or whether these larval stages evade the host immune system in the same way. The objective of this study wa…
Effect of water content and temperature on seed longevity of seven Brassicaceae species after 5 years of storage.
2014
Maximising seed longevity is crucial for genetic resource preservation and longevity of orthodox seeds is determined by environmental conditions (water content and temperature). The effect of water content (down to 0.01 g·H₂O·g(-1) ) on seed viability was studied at different temperatures for a 5-year storage period in taxonomically related species. Seeds of seven Brassicaceae species (Brassica repanda, Eruca vesicaria, Malcolmia littorea, Moricandia arvensis, Rorippa nasturtium-aquaticum, Sinapis alba, Sisymbrium runcinatum) were stored at 48 environments comprising a combination of eight water contents, from 0.21 to 0.01 g·H₂O·g(-1) DW and six temperatures (45, 35, 20, 5, -25, -170 °C). S…
Continental weathering and climatic changes inferred from clay mineralogy and paired carbon isotopes across the early to middle Toarcian in the Paris…
2014
Abstract Lower Toarcian strata (Lower Jurassic) have been extensively studied with a view to understanding the oceanographic, climatic and biological processes that drove the Earth's system into an Oceanic Anoxic Event (OAE). For this time period, the evolution of the European marine seaways is now relatively well constrained owing to multiple geochemical studies, but investigations regarding climatic trends in the continental realm remain sparse. In the present study, we test the clay mineralogy as a continental climate-sensitive proxy in the well-documented Sancerre core (southern Paris Basin). We compare variations in the kaolinite content with p CO 2 fluctuations (derived from paired ca…
Corticotomies as a surgical procedure to accelerate tooth movement during orthodontic treatment : a systematic review
2015
Background One of the main aims of orthodontists is to reduce the treatment time as much as possible, particularly in view of the rise in demand for orthodontic treatment among adult patients. The objective of this systematic review was to examine the effectiveness of corticotomy as a surgical procedure that accelerates orthodontic tooth movement, together with its possible adverse effects. Material and Methods A systematic review of articles in 4 databases, Pubmed, Cochrane, Scopus and Embase, complemented by a manual search, identified 772 articles. The duplicates were eliminated and a critical reading of titles and abstracts led to the rejection of articles that did not meet the objectiv…
The Efficacy and Safety of Topiramate in the Prevention of Pediatric Migraine: An Update Meta-Analysis
2020
Background: Migraine is the most common acute primary headache in children and adolescents. In 2014, topiramate became the first preventive drug for migraine, approved by the Food and Drug Administration (FDA) for adolescents. This meta-analysis was aimed to evaluate the efficacy and safety of topiramate in the prevention of pediatric migraine.Methods: We searched the PubMed, EMBASE, Cochrane Library, and Chinese National Knowledge Infrastructure (CNKI) databases up to June 2019 for eligible randomized controlled trials (RCTs). The primary outcomes were mean migraine days per month, ≥50% reduction rate, and Pediatric Migraine Disability Assessment Scale (PedMIDAS) scores. RevMan5.3 software…
Impacts of oak deforestation and rainfed cultivation on soil redistribution processes across hillslopes using 137Cs techniques
2021
Abstract Background As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. Methods In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects …
Plant diversity effects on the water balance of an experimental grassland
2014
In the literature, contrasting effects of plant species richness on the soil water balance are reported. Our objective was to assess the effects of plant species and functional richness and functional identity on soil water contents and water fluxes in the experimental grassland of the Jena Experiment. The Jena Experiment comprises 86 plots on which plant species richness (0, 1, 2, 4, 8, 16, and 60) and functional group composition (zero to four functional groups: legumes, grasses, tall herbs, and small herbs) were manipulated in a factorial design. We recorded meteorological data and soil water contents of the 0·0–0·3 and 0·3–0·7 m soil layers and calculated actual evapotranspiration (ETa)…
A new species of Hedya Hübner from Iran with proposed rearrangement of some species currently assigned to Metendothenia Diakonoff (Lepidoptera: Tortr…
2011
Hedya tritofa, new species, is described and illustrated based on eleven males and five females collected in northern Iran (Gilan, Mazandaran, and Golestan provinces). Morphology and diagnostic characters of Hedya Hubner, 1825, Metendothenia Diakonoff, 1973, the Olethreutes group of genera, and the Neopotamia group of genera are discussed. We propose the resurrection of the combinations Hedya atropunctana (Zetterstedt, 1840), revised status, and H. separatana (Kearfott, 1907), revised status, and the new combination H. inouei (Kawabe, 1987).