Search results for "RP"
showing 10 items of 25034 documents
Antimicrobial secondary metabolites from the medicinal plant Crinum glaucum A. Chev. (Amaryllidaceae)
2020
Abstract Medicinal plants are known as sources of potential antibacterial compounds including alkaloids. The aim of the present study was to evaluate the antibacterial activities of the extract, fractions, and some secondary metabolites isolated from the leaves of Crinum glaucum A. Chev. (Amaryllidaceae). The antibacterial activities were performed with the ethanol (EtOH) extract, as well as with ethyl acetate (EtOAc) and n-butanol (n-BuOH) fractions. Repeated column chromatography of the fractions led to the isolation of several compounds and their structures were elucidated mainly by means of extensive spectroscopic analysis [(one-dimensional (1D) and two-dimensional (2D) nuclear magnetic…
Effects of the filter-feeding benthic bivalve corbicula fluminea on plankton community and water quality in aquatic ecosystems: A mesocosm study
2021
The influence of filter-feeding bivalves on plankton communities, nutrients, and water quality in a given aquatic ecosystem is so profound that they can be considered ecosystem engineers. In a 70-day mesocosm experiment, we tested the hypothesis that Corbicula fluminea would change plankton community structure by reducing small zooplankton and large phytoplankton and improve water quality by reducing nutrients. We monitored levels of nitrogen and phosphorus, organic suspended solids (OSS), and light at the sediment surface. Within the plankton, phytoplankton biomass (as Chl a, >
Context-dependent coloration of prey and predator decision making in contrasting light environments
2022
A big question in behavioral ecology is what drives diversity of color signals. One possible explanation is that environmental conditions, such as light environment, may alter visual signaling of prey, which could affect predator decision-making. Here, we tested the context-dependent predator selection on prey coloration. In the first experiment, we tested detectability of artificial visual stimuli to blue tits (Cyanistes caeruleus) by manipulating stimulus luminance and chromatic context of the background. We expected the presence of the chromatic context to facilitate faster target detection. As expected, blue tits found targets on chromatic yellow background faster than on achromatic gre…
Genetic roadmap of the Arctic: plant dispersal highways, traffic barriers and capitals of diversity.
2013
This is the peer reviewed version of the following article: Eidesen, P.B., Ehrich, D., Bakkestuen, V., Alsos, I.G., Gilg, O., Taberlet, P. & Brochmann, C. (2013). Genetic roadmap of the Arctic: plant dispersal highways, traffic barriers and capitals of diversity. New Phytologist, 200(3), 898-910. https://doi.org/10.1111/nph.12412, which has been published in final form at https://doi.org/10.1111/nph.12412. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. We provide the first comparative multispecies analysis of spatial genetic structure and diversity in the circumpolar Arctic using a common strategy for sam…
Climate Change and Migration for Scandinavian Saami: A Review of Possible Impacts
2019
Migration, especially of indigenous peoples, related to or influenced by climate change continues to gain increasing research and policy attention. Limited material remains for this topic for Scandinavia&rsquo
Drosophila Evolution over Space and Time (DEST) : A New Population Genomics Resource
2021
Drosophila melanogaster is a leading model in population genetics and genomics, and a growing number of whole-genome datasets from natural populations of this species have been published over the last years. A major challenge is the integration of disparate datasets, often generated using different sequencing technologies and bioinformatic pipelines, which hampers our ability to address questions about the evolution of this species. Here we address these issues by developing a bioinformatics pipeline that maps pooled sequencing (Pool-Seq) reads from D. melanogaster to a hologenome consisting of fly and symbiont genomes and estimates allele frequencies using either a heuristic (PoolSNP) or a…
How to Assess the Ecological Status of Highly Humic Lakes? Development of a New Method Based on Benthic Invertebrates
2021
Highly humic lakes are typical for the boreal zone. These unique ecosystems are characterised as relatively undisturbed habitats with brown water, high acidity, low nutrient content and lack of macrophytes. Current lake assessment methods are not appropriate for ecological assessment of highly humic lakes because of their unique properties and differing human pressures acting on these ecosystems. This study proposes a new approach suitable for the ecological status assessment of highly humic lakes impacted by hydrological modifications. Altogether, 52 macroinvertebrate samples from 15 raised bog lakes were used to develop the method. The studied lakes are located in the raised bogs at the c…
The unique inflorescence structure of Dorema aucheri (Apiaceae): An adaptation to the arid environment
2021
Abstract Arid environments demand specific adaptations from plants in vegetative and reproductive systems. Self–compatibility, high pollen production and few well developed fruits are adapted to increase sexual reproductive success. Dorema aucheri is an arid–adapted, perennial monocarpic species endemic to southern Iran. It has a unique inflorescence structure. In this study, significance of inflorescence architecture for reproductive success was investigated in a wild population. The huge yellow inflorescences were frequently visited by manifold insects. The species is andromonoecious and spatially subdivided in a distal part with perfect flowers and a proximal part with male flowers. Flow…
Effects of photoperiod on life-history and thermal stress resistance traits across populations of Drosophila subobscura
2019
Introduction Organisms use environmental cues to match their phenotype with the future availability of resources and environmental conditions. Changes in the magnitude and frequency of environmental cues such as photoperiod and temperature along latitudes can be used by organisms to predict seasonal changes. While the role of temperature variation on the induction of plastic and seasonal responses is well established, the importance of photoperiod for predicting seasonal changes is less explored. Materials and methods Here we studied changes in life‐history and thermal stress resistance traits in Drosophila subobscura in response to variation in photoperiod (6:18, 12:12 and 18:6 light:dark …
Presence of uradenia in male adults of the genus Dismegistus (Hemiptera: Heteroptera: Parastrachiidae)
2018
Uradenia, often referred to as paragenital glands, are usually voluminous paired exocrine glands located ventrally in the abdomen mostly on the intersegmental membrane between abdominal segments (= urites) VII-VIII or VIII-IX, depending on sex or the taxon. They have been previously recorded from eight pentatomomorphan families belonging to Coreoidea, Lygaeoidea and Pyrrhocoroidea (Hemiptera: Heteroptera), found either in males, females or both sexes, and were thought to be absent in Pentatomoidea. We report here the first instance of uradenia in a pentatomoid genus, the African Dismegistus Amyot & Serville, 1843 (Parastrachiidae). Only the male adult possesses uradenia located on the i…