Search results for "Activity"
showing 10 items of 7178 documents
Anthropogenic threats drive spatio-temporal responses of wildcat on Mt. Etna
2021
Human expansion can cause disturbance and intrusion of invasive species, which are detrimental to small carnivores. We investigated how European wildcats responded to disturbance from mushroom collectors, cattle and feral pigs in Sicily, Italy. We used detections from 76 cameras over 2 surveys (2015–2016 and 2018; camera days = 1985) to run occupancy and co-occurrence models and estimate overlap in activity patterns between species pairs. During 2015–2016, wildcats were detected at the same location with cattle, mushroom hunters and feral pigs at 14.4%, 26.3% and 17.1% of cameras. During 2018, wildcats were detected at the same location with cattle, mushroom hunters and feral pigs at 7.8%, …
Evidence for specific, high-affinity binding sites for a proteinaceous elicitor in tobacco plasma membrane
1995
Abstract Binding of cryptogein, a proteinaceous elicitor, was studied on tobacco plasma membrane. The binding of the [125I]cryptogein was saturable, reversible and specific with an apparent Kd of 2 nM. A single class of cryptogein binding sites was found with a sharp optimum pH for binding at about pH 7.0. The high-affinity correlates with cryptogein concentrations required for biological activity in vivo.
Plant species identities and fertilization influence on arbuscular mycorrhizal fungal colonisation and soil bacterial activities
2016
International audience; Plant species influence soil microbial communities, mainly through their functional traits. However, mechanisms underlying these effects are not well understood, and in particular how plant/ microorganism interactions are affected by plant identities and/or environmental conditions. Here, we performed a greenhouse experiment to assess the effects of three plant species on arbuscular mycorrhizal fungal (AMF) colonization, bacterial potential nitrification (PNA) and denitrification activities (PDA) through their functional traits related to nitrogen acquisition and turnover. Three species with contrasting functional traits and strategies (from exploitative to conservat…
Kinetic studies on protoporphyrinogen oxidase inhibition by diphenyl ether herbicides
1991
Diphenyl ethers (DPEs) and related herbicides are powerful inhibitors of protoporphyrinogen oxidase, an enzyme involved in the biosynthesis of haems and chlorophylls. The inhibition kinetics of protoporphyrinogen oxidase of various origins by four DPEs, (methyl)-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (acifluorfen and its methyl ester, acifluorfen-methyl), methyl-5-[2-chloro-4-(trifluoromethyl) phenoxy]-2-chlorobenzoate (LS 820340) and methyl-5-[2-chloro-5-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid (RH 5348), were studied. The inhibitions of the enzymes from maize (Zea mays) mitochondrial and etiochloroplastic membranes and mouse liver mitochondrial membranes were com…
Inhibitory Effect of Azamacrocyclic Ligands on Polyphenol Oxidase in Model and Food Systems
2020
[EN] Enzymatic browning is one of the main problems faced by the food industry due to the enzyme polyphenol oxidase (PPO) provoking an undesirable color change in the presence of oxygen. Here, we report the evaluation of 10 different azamacrocyclic compounds with diverse morphologies as potential inhibitors against the activity of PPO, both in model and real systems. An initial screening of 10 ligands shows that all azamacrocyclic compounds inhibit to some extent the enzymatic browning, but the molecular structure plays a crucial role on the power of inhibition. Kinetic studies of the most active ligand (L2) reveal a S-parabolic I-parabolic noncompetitive inhibition mechanism and a remarkab…
Inhibition of adenosine trephosphatase activity from a plasma membrane fraction of acer pseudoplatanus cells by 2,2,2-trichloroethyl 3,4-dichlorocarb…
1986
2,2,2-Trichloroethyl 3,4-dichlorocarbanilate (SW26) is toxic for Acer pseudoplatanus cell cultures. It inhibited the cellular proton extrusion and depolarized the plasmalemma. In vitro, it inhibited the plasma membrane ATPase. SW 26 was also inhibitory to membrane ATPases of other origins-plant (maize shoot), fungus (Schizosaccharomyces pombe), and animal (dog kidney)-with about the same efficiency (7.5 micromolar < I(50) < 22 micromolar). It did not inhibit the oligomycin-sensitive ATPase from purified plant mitochondria, nor molybdate-sensitive soluble phosphatases. SW26 was more specific for plasma membrane ATPases than diethylstilbestrol or vanadate. A Lineweaver-Burk plot analysis show…
The effect of abrasive pretreatment on the drying kinetics and phenolic compounds in goji berries ( Lycium barbarum L.)
2020
The paper investigated the effect of a physical surface abrasion of goji berries on drying kinetics and the evolution of phenolic compounds at 323, 333, and 343 K. A diffusion model was developed to describe the drying process. The effective diffusion coefficient estimated by the model ranged from 7.5 × 10–9 to 4.2 × 10–8 m2/s for cylinder and 2.0 × 10–9 to 1.15 × 10–8 m2/s for sphere for untreated samples (UTR). Higher values were found for treated samples (TR) (from 2.50 × 10–8 to 1.20 × 10–7 m2/s for cylinder and 8.0 × 10–9 to 2.70 × 10–8 m2/s for sphere). For the UTR samples, the values of activation energy were found to be 79.5 and 80.8 kJ/mol, respectively, in the cylinder and sphere …
An overview of natural antimicrobials role in food
2017
The present paper aims to review the natural food preservatives with antimicrobial properties emphasizing their importance for the future of food manufacturing and consumers' health. The extraction procedures applied to natural antimicrobials will be considered, followed by the description of some natural preservatives' antimicrobial mechanism of action, including (i) membrane rupture with ATP-ase activity inhibition, (ii) leakage of essential biomolecules from the cell, (iii) disruption of the proton motive force and (iiii) enzyme inactivation. Moreover, a provenance-based classification of natural antimicrobials is discussed by considering the sources of origin for the major natural prese…
A new ursane-type triterpene oxoglucopyranoside from Crossopteryx febrifuga.
2019
Abstract A new saponin, 3-O-β-d-3-oxo-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (1), was isolated from the methanol extract of stem bark of Crossopteryx febrifuga together with the known 3β-d-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (2), shanzhiside methyl ester (3), shanzhiside (4), β-sitosterol (5), β-sitosterol-3-O-β-d-glucopyranoside (6), ursa-12,20(30)-diene-27,28-dioic acid (7), hederagenin (8), and oleanolic acid (9). The structures were established by comprehensive interpretation of their spectral data 1D- (1H and 13C), 2D-NMR (1H-1H COSY, HMQC, HMBC), spectroscopic, and electrospray ionisation time-of-flight mass spectrometry analysis. The isolated compounds …
Monitoring the reproductive activity in captive bred female ball pythons (P. regius) by ultrasound evaluation and noninvasive analysis of faecal repr…
2018
The royal python (Python regius) is commonly bred in captivity. To have a successful breeding season, accurate monitoring of the reproductive activity is necessary. The use of non-invasive monitoring methods in exotics is important in order to minimize stress. For this purpose ultrasound has been anecdotally used to monitor royal python reproductive activity. However, there is limited information regarding the reproductive cycle of this species. The aim of the present study is to monitor the female reproductive cycle of the royal python using ultrasonography and gonadal steroid metabolite measurements in the faeces. The reproductive activity of one hundred twenty-nine adult female P. regius…