Search results for "traction"

Volatile organic compounds in wild fungi from Mediterranean forest ecosystems

2017

AbstractHead Space-Solid Phase Micro Extraction (HS-SPME) extractions and Gas Chromatography-Mass Spectrometry (GC-MS) analysis allowed the identification of 72 different compounds isolated from 7 different wild inedible fungi collected in Mediterranean forest ecosystems. The VOCs reported in this study, including a total of 5 esters, 17 alcohols, 14 aldehydes, 9 ketones, 18 terpenes and 9 other compounds, have been never characterized before for Tricholoma ustaloides, Hygrophorus cossus, Russula foetens and Mycena pura.

2018

Chemically defended animals often display conspicuous colour patterns that predators learn to associate with their unprofitability and subsequently avoid. Such animals (i.e. aposematic), deter predators by stimulating their visual and chemical sensory channels. Hence, aposematism is considered to be ‘multimodal’. The evolution of warning signals (and to a lesser degree their accompanying chemical defences) is fundamentally linked to natural selection by predators. Lately, however, increasing evidence also points to a role of sexual selection shaping warning signal evolution. One of the species in which this has been shown is the wood tiger moth, Arctia plantaginis, which we here put forward…

Love at first sniff: a spermatophore-associated pheromone mediates partner attraction in a collembolan species

2017

Mate choice is essential in most animals, as a good choice of mating partner largely determines reproductive success. Much evidence shows that olfactory cues play an important role in mate choice. However, the integration of chemical, visual and acoustic cues, often used when both partners meet, makes it hard to test whether olfaction alone can mediate reproductive decisions. Interestingly, several invertebrates have adopted a mating system where males deposit their sperm (packed in spermatophores) in the environment for females to pick up with no visual contact between the sexes. In this case the male cue is conveyed by the spermatophore only. Earlier studies on a species with indirect spe…

Topological congruence between phylogenies of Anacanthorus spp. (Monogenea: Dactylogyridae) and their Characiformes (Actinopterygii) hosts: A case of…

2017

Cophylogenetic studies aim at testing specific hypotheses to understand the nature of coevolving associations between sets of organisms, such as host and parasites. Monogeneans and their hosts provide and interesting platform for these studies due to their high host specificity. In this context, the objective of the present study was to establish whether the relationship between Anacanthorus spp. with their hosts from the upper Paraná River and its tributaries can be explained by means of cospeciation processes. Nine fish species and 14 monogenean species, most of them host specific, were studied. Partial DNA sequences of the genes RAG1, 16S and COI of the fish hosts and of the genes ITS2, …

Extraction of lipids from wet microalga Auxenochlorella protothecoides using pulsed electric field treatment and ethanol-hexane blends

2017

Abstract Pulsed Electric Field (PEF) treatment was used as pre-treatment on the microalgae strain Auxenochlorella protothecoides (A.p.) prior to organic solvent extraction of lipids. Experiments were performed on fresh biomass from mixotrophic or autotrophic culture which both had an evaluated lipid content of 30–35% of cell dry weight. Lipid yield was determined gravimetrically and compared to the reference lipid content assessed by bead-milling and subsequent Soxhlet extraction. The biomass was concentrated at 10% w/w solids prior to PEF-treatment and further dewatered afterwards to approximately 25% w/w before extraction. PEF-treatment with an energy input of 1.5 MJ per kilogram of dry m…

Variation in gene expression within clones of the earthworm Dendrobaena octaedra

2017

Gene expression is highly plastic, which can help organisms to both acclimate and adapt to changing environments. Possible variation in gene expression among individuals with the same genotype (among clones) is not widely considered, even though it could impact the results of studies that focus on gene expression phenotypes, for example studies using clonal lines. We examined the extent of within and between clone variation in gene expression in the earthworm Dendrobaena octaedra, which reproduces through apomictic parthenogenesis. Five microsatellite markers were developed and used to confirm that offspring are genetic clones of their parent. After that, expression of 12 genes was measured…

Immunity and other defenses in pea aphids, Acyrthosiphon pisum

2010

Background Recent genomic analyses of arthropod defense mechanisms suggest conservation of key elements underlying responses to pathogens, parasites and stresses. At the center of pathogen-induced immune responses are signaling pathways triggered by the recognition of fungal, bacterial and viral signatures. These pathways result in the production of response molecules, such as antimicrobial peptides and lysozymes, which degrade or destroy invaders. Using the recently sequenced genome of the pea aphid (Acyrthosiphon pisum), we conducted the first extensive annotation of the immune and stress gene repertoire of a hemipterous insect, which is phylogenetically distantly related to previously ch…

Isolation and determination of phenolic compounds from freshwater Cladophora glomerata

2020

Abstract Marine algae biomass has gained widespread interest in the world of science and many industries. The growing number of publications proves that these algae are an interesting and essential natural resource. This interest is due to the presence of a variety of biologically active compounds that give algae extracts a broad spectrum of biological and functional properties. However, there is little data on the chemical composition of algae obtained from freshwater. This work focuses on the isolation and determination of phenolic compounds from freshwater algae of the species Cladophora glomerata. Different types of extraction and extractants were used to isolate these bioactive compoun…

A one step enhanced extraction and encapsulation system of cornelian cherry (Cornus mas L.) polyphenols and iridoids with β-cyclodextrin

2021

Abstract The objective of this study was simultaneous extraction and encapsulation of cornelian cherry active principles. As an encapsulating agent, β-cyclodextrin (β-CD) was used to enhance the ultrasound-assisted extraction of cornelian cherry polyphenols and iridoids. Lyophilized cornelian cherry fruit was extracted by four different solvents: pure water, 50% aqueous ethanol (conventional system), 1.5% β-CD water solution and 1.5% β-CD aqueous ethanol solution. The highest enhancement of the extraction efficiency was observed for flavonoids and anthocyanins, especially for cyaniding 3-galactoside and pelargonidin 3-galactoside. Water-ethanolic extract was used to form inclusion complexes…

Pulsed electric field and pH assisted selective extraction of intracellular components from microalgae Nannochloropsis

2015

Abstract The study was aimed at investigation of the potential of pulsed electric field (PEF) pre-treatment as a preliminary step of pH-assisted aqueous extraction of algae components from microalgae Nannochloropsis suspensions. The PEF and sonication (S) were compared as pretreatment methods. They were applied at normal (pH = 8.5) and basic (pH = 11) conditions, and supplementary basic extraction (at pH = 11) was done. The extracts were analyzed for content of pigments, proteins, carbohydrates, total phenolic compounds and antioxidant capacity. The colloidal stability of PEF- and S-pretreated suspensions was also evaluated. The data evidence that PEF technique allows selective extraction o…