Search results for "RF"
showing 10 items of 23683 documents
RNA uridylation and decay in plants
2018
RNA uridylation consists of the untemplated addition of uridines at the 3′ extremity of an RNA molecule. RNA uridylation is catalysed by terminal uridylyltransferases (TUTases), which form a subgroup of the terminal nucleotidyltransferase family, to which poly(A) polymerases also belong. The key role of RNA uridylation is to regulate RNA degradation in a variety of eukaryotes, including fission yeast, plants and animals. In plants, RNA uridylation has been mostly studied in two model species, the green algae Chlamydomonas reinhardtii and the flowering plant Arabidopsis thaliana . Plant TUTases target a variety of RNA substrates, differing in size and function. These RNA substrates include …
Evaporation from soils of different texture covered by layers of water repellent and wettable soils
2020
Water repellent soils are able to channel water deep into the soil profile by fingered flow, minimising water storage in the water repellent top layer where water is most susceptible to evaporation. To date, the effect of water repellent or wettable surface layer on evaporation from wet sublayer has only been reported for coarse materials, and an increase in water repellency led to a greater delay in water evaporation. The objective of this study was to assess the effect of water repellent vs. wettable top layers with different thickness on water evaporation from coarse and fine texture subsoils that were pre-moistened. Clay loam soil samples were taken from Pinus pinaster woodland of Ciavo…
Glycolipid Biosurfactant Production from Waste Cooking Oils by Yeast: Review of Substrates, Producers and Products
2021
Biosurfactants are a microbially synthesized alternative to synthetic surfactants, one of the most important bulk chemicals. Some yeast species are proven to be exceptional biosurfactant producers, while others are emerging producers. A set of factors affects the type, amount, and properties of the biosurfactant produced, as well as the environmental impact and costs of biosurfactant’s production. Exploring waste cooking oil as a substrate for biosurfactants’ production serves as an effective cost-cutting strategy, yet it has some limitations. This review explores the existing knowledge on utilizing waste cooking oil as a feedstock to produce glycolipid biosurfactants by yeast. The review f…
Thermal variability during ectotherm egg incubation: A synthesis and framework.
2020
Natural populations of ectothermic oviparous vertebrates typically experience thermal variability in their incubation environment. Yet an overwhelming number of laboratory studies incubate animals under constant thermal conditions that cannot capture natural thermal variability. Here, we systematically searched for studies that incubated eggs of ectothermic vertebrates, including both fishes and herpetofauna, under thermally variable regimes. We ultimately developed a compendium of 66 studies that used thermally variable conditions for egg incubation. In this review, we qualitatively discuss key findings from literature in the compendium, including the phenotypic effects resulting from diff…
UV-screening and springtime recovery of photosynthetic capacity in leaves of Vaccinium vitis-idaea above and below the snow pack
2019
International audience; Evergreen plants in boreal biomes undergo seasonal hardening and dehardening adjusting their photosynthetic capacity and photoprotection; acclimating to seasonal changes in temperature and irradiance. Leaf epidermal ultraviolet (UV)-screening by flavonols responds to solar radiation, perceived in part through increased ultraviolet-B (UV-B) radiation, and is a candidate trait to provide cross-photoprotection. At Hyytiälä Forestry Station, central Finland, we examined whether the accumulation of flavonols was higher in leaves of Vaccinium vitis-idaea L. growing above the snowpack compared with those below the snowpack. We found that leaves exposed to colder temperature…
Re-examining the rare and the lost : a review of fossil Tortricidae (Lepidoptera)
2018
We re-evaluate eleven fossils that have previously been assigned to the family Tortricidae, describe one additional fossil, and assess whether observable morphological features warrant confident assignment of these specimens to this family. We provide an overview of the age and origin of the fossils and comment on their contribution towards understanding the phylogeny of the Lepidoptera. Our results show that only one specimen, Antiquatortia histuroides Brown & Baixeras gen. and sp. nov., shows a character considered synapomorphic for the family. Six other fossils ( Electresia zalesskii Kusnezov, 1941; Tortricidrosis inclusa Skalski, 1973; Tortricites skalskii Kozlov, 1988; Tortricibaltia d…
Symbiotic polydnavirus and venom reveal parasitoid to its hyperparasitoids
2018
Symbiotic relationships benefit organisms in utilization of new niches. In parasitoid wasps, symbiotic viruses and venom that are injected together with wasp eggs into the host caterpillar suppress immune responses of the host and enhance parasitoid survival. We found that the virus also has negative effects on offspring survival when placing these interactions in a community context. The virus and venom drive a chain of interactions that includes the herbivore and its food plant and attracts the hyperparasitoid enemies of the parasitoid. Our results shed new light on the importance of symbionts associated with their host in driving ecological interactions and highlight the intricacy of how…
Bioethanol and lipid production from the enzymatic hydrolysate of wheat straw after furfural extraction
2018
This study investigates biofuel production from wheat straw hydrolysate, from which furfural was extracted using a patented method developed at the Latvian State Institute of Wood Chemistry. The solid remainder after furfural extraction, corresponding to 67.6% of the wheat straw dry matter, contained 69.9% cellulose of which 4% was decomposed during the furfural extraction and 26.3% lignin. Enzymatic hydrolysis released 44% of the glucose monomers in the cellulose. The resulting hydrolysate contained mainly glucose and very little amount of acetic acid. Xylose was not detectable. Consequently, the undiluted hydrolysate did not inhibit growth of yeast strains belonging to Saccharomyces cerev…
Diminishing returns of inoculum size on the rate of a plant RNA virus evolution
2017
[EN] Understanding how genetic drift, mutation and selection interplay in determining the evolutionary fate of populations is one of the central themes of Evolutionary Biology. Theory predicts that by increasing the number of coexisting beneficial alleles in a population beyond some point does not necessarily translates into an acceleration in the rate of evolution. This diminishing-returns effect of beneficial genetic variability in microbial asexual populations is known as clonal interference. Clonal interference has been shown to operate in experimental populations of animal RNA viruses replicating in cell cultures. Here we carried out experiments to test whether a similar diminishing-re…
Does silica concentration and phytolith ultrastructure relate to phytolith hardness?
2017
Abstract Grasses are an important part of the forage of many herbivorous mammals and their phytoliths have long been regarded as the most important agent of tooth wear. Recent work has challenged this “paradigm” in finding evidence 1. of native phytoliths to be much softer then tooth enamel and 2. indicating, that phytolith hardness is highly variable, 3. prone to methodology and 4. not easy to be related to habitat conditions. We conduct controlled silica-cultivations measuring SiO2 content in the common forage grass Themeda triandra. Phytoliths are extracted natively, and nano-indentation values are measured. Phytolith hardness in Themeda triandra is found to be independent of silicate av…